Both my daughters (attorney and teacher) shop ModCloth: https://www.modcloth.com/shop/work-dresses. Look at blazers, etc.
Variety of sizes; easy to order; free shipping over a reasonable amount; easy returns (with prepaid label). Some stuff looks cheap, some not-so-cheap.
Nordstrom Rack has a good selection of Theory clothes which is great quality, classic, very work appropriate, and flattering on young women’s figures. It is normally pricey, but Nordstrom Rack makes it affordable and it will last.
I second the ModCloth idea. Lots of choices in many different size ranges, and not so cookie cutter in style. Plus it’s so easy for her to browse herself to see what she likes. (As the mom of a daughter with very definite ideas of style at age 17, I can’t imagine a young adult who would want to defer all this to a parent.) The reviews are very helpful. If everyone says the sizing is off or the material is cheap, listen to that advice. And as one who’s been burned a couple of times, never buy “final sale” even if it’s really inexpensive because then you can’t return it if it doesn’t work out. On the other hand, some of my favorite dresses are from ModCloth.
One more thing to consider: If the job at the “science and technology office” involves lab work, be sure to consider functional aspects, depending on the type of lab involved. For example, if there is machinery involved, clothing that could easily get caught in the machinery would be a bad idea (and long hair would have to be secured for the same reason).
OP said it is not a lab position; sounds more like a tech transfer office. But good points. 
DD got a personal shopper at Nordstrom to help her put some outfits together. They knew she was just starting out and considered that in selecting the pieces, although she did buy some more expensive shoes that she has gotten a lot of use from. But having someone that wasn’t Mom to help her pick a “look” in the city where she would be working was valuable.
If I had to start over, I would pick a work uniform and stick to it. Similar pants, jackets, blouses, shoes, same look, easy to replace pieces as they age out. That makes it easier to know what bargains to choose at the Rack or Steinmart.
What is your D’s usual style? I think it’s important to keep “her” in her wardrobe. If you told me I had to start wearing the pants and blazer that everyone else in the office was wearing I think I’d go crazy. She can try and blend her style with what is appropriate. Does she prefer pants over skirts/dresses? Or the opposite?
I agree with Rack and I’ll also throw in a JCrew Factory or Outlet for some nice but affordable young options.
Edited to also add that my two 20-somethings love Madewell - you might find some good clearance pants/dresses this time of year. If that’s her style.
Both of my 20 something Ds like bricks and mortar Nordstrom Rack, Loft, BR and TJ Maxx. D1 will wear whatever I buy her. D2 is the family fashionista. She has a knack for mixing high end and low end. She always gets compliments on outfits and I am continuously surprised when she tells me a top, jewelry or scarf is from Target! Both Ds like the fit of Editor pants from Express as they are wash and wear and maintain shape. D2 has some pairs that have lasted for 5 years! Neither wants pants that have to be dry cleaned. D2 is a CPA and wears dressier clothes (suits and blazers). I stalk Rack, White House Black Market and TJ Maxx for these high end ticket items. Don’t ever pay full price at Ann Taylor or Loft. They always have sales.
For what it’s worth, JC Penneys currently has some LeSuit suits on sale.
Macy’s and Nordstrom Rack should provide everything you need and will be relatively affordable. Once you get a Macy’s credit card, it seems like everything is at least 20% off!
Macy’s and Nordstrom Rack should provide everything you need and will be relatively affordable. Once you get a Macy’s credit card, it seems like everything is at least 20% off!
Depending upon that season’s trends it may be easier to mix the inexpensive tops (from Target, Forever 21, Primark, or H&M) with your better quality pants. The past few years it has been hard - the recent looks of off the shoulder, strappy revealing backs, or sweaters with a loose see through knit - will not work in an office.
We just did a wardrobe (potential interviewing) shop at the outlet mall. Banana republic, J. crew and Anne Taylor were our top picks. D tends more to a vintage look and had no dress pants (likes skirts and dresses), so we got a couple of pairs of dress pants. And a jacket that would go with pants and a dress she already owns, so options. At Banana Republic and J. Crew, once you find a fit/cut you like, you can check the sales online as you need to. There are always discounts at these places. LOFT also has good sales often. You just have to find a place with cut that fits. D1 likes fit of J.Crew, D2 had better luck at Banana Republic.
If she might ever need a suit (client meetings, conferences) then buy one basic like black with jacket and pants or skirt so that in future you have one thing that goes together. Once you buy pants, you can’t always go back and find a jacket that matches - even blacks don’t always match up.
This is a mom/generational thing, but I made sure D had one pair of pants that met my criteria of dress pants. Ds like very skinny, me not so much and I think little straighter cut better. Of course, if your D has job (not job hunting) so she may be able to be a little more trendy. My oldest is teaching and wears skinnier stuff that I would think appropriate but she always looks nice. However when job hunting, even her advisor said to not go too skinny.
BTW, lots of these places give student discounts for those of you shopping for students. BR gave it on top of outlet sale price. Ended up with all pants being between $30-40 a pair for good quality.
For online shopping, 6pm and Ruelala often have terrific deals on name brands. Places like RealReal sell consignment, but their pieces are always in very good shape and oftentimes have not been worn.
And of course, in our kiddo’s case, the best and cheapest place to shop is her mom’s closet. Lol. She always finds terrific deals on Boss and Max Mara in there and even scored a pair of Jimmy Choo sandals recently. 
I just read that Modcloth is now owned by Walmart.
One of my D’s worked for a very conservative company and the understood dress code was a suit in black, navy or charcoal to be worn with mid to low heeled pumps. Jacket could be taken off at your desk but whenever you walked out of your office you needed to be wearing your jacket. She found Ann Taylor and Banana Republic the best for suits as they sell petite and separates. Tops came from Macy, Loft and even Old Navy. She now has a different job where she wears AG brand colored pants with a nice shirt. Her go to shoe now is a bootie. Her childhood closet is now filled with business attire that she will probably never wear again.
My other D works in a casual law office. She wears nice jeans and a nice top with flats. The attorney wears the same unless she is going to court.
I suggest unless she has a clear picture of what others wear I would buy only a few things till she knows what she really wants. My D worked in HR at her last job and she tells the story when a new hire (recent college grad) who was entering the management training program came on her first day in a brightly colored suit. It was clearly a case of someone who had not been paying attention at her interviews.
Congrats to her! My daughter bought basic items at NY & Co. (which has clothes for tall people!) and Macy’s. She purchased a few nice pairs of slacks, blouses, cardigans and flats.
What about less upscale places like Penneys and Macys? A lot depends on how casual the place is and her role. Plus her budget.
If she is to be facing the public it is different than if hired as a scientist/lab person. Many of us STEM women don’t care that much about appearances- more important things to do. As an anesthesiologist I generally lived in scrubs during the day (would NEVER wear them outside the hospital) and did not bother dressing up at all. As a chemistry undergrad- definitely nothing I would mind spills on.
Son started in computer software wearing casual shirts, now just T shirts (noncollared). So much depends on the workplace. He dressed up more for the interviews- at his first place he discarded his tie after a bit he reported.
She should contact her new place about what to wear now that she has been hired. Hopefully no one really cares. I feel sorry for those who need to dress in the business world- so superficial. As a client I never was impressed with that. Outlier and glad of it.
My mid-twenties daughter started her first stateside job about a month ago. For the last year she was working in a professional setting in the tropics so having appropriate clothing wasn’t initially a concern. Now, with the hint of fall in the air and a paycheck in her pocket, she’s thinking about doing some shopping. She was disappointed to hear that The Limited had gone out of business as she had good luck with the basics there. Now she’s talking about trying Nordstrom’s subscription service, Trunk Club, to build on what she already has. It appears to have some advantages over Stitch Fix, including being able to preview and edit your box online before it is sent and free alterations.
The Limited near me is open-- I was there yesterday.
I imagine she could find what she’s looking for on their website.
I got a job at a college last year after working for myself for over a decade. I had a couple of business casual outfits (slacks and blazers) that I wore for interviews, but after I got hired I had to go shopping. None of our local stores had anything worth wearing so I had to order online or visit consignment shops.
J. Crew has nice pants, so I stocked up on those. Blazers have been more difficult to find because I’m on the tall side and the overall length is shorter than I like or the sleeves aren’t long enough. I’d love to know where to find well made blazers that fit well. I had to go to DSW for leather shoes because most stores don’t carry my size. So much seems to depend on what the current fashion trend is. Last year it appeared to be flimsy, shoulder baring, see through shirts and skintight stretchy pants. You’ll have to visit your local shops to see what’s out there.
I’d suggest giving her enough money so she can buy a few separates to get her started. They can be dressed up or down with accessories.