Go to TJMaxx/HomeGoods and look for discounted beautiful Le Creuset. A dutch oven - even not the larger size - would be perfect. Fill it with some gourmet food items, nice utensils, etc.
I love the cookware idea! And then some fancy cooking stuff she’d never splurge on, such as infused olive oils.
Obviously, this is not a suggestion of a gift for the OP, just a comment. I would not dismiss a brand because it is a “brand name.” Hermes is different form other designers in that it hires and promotes independent artists by sponsoring their designs on its scarves, bracelets, and ties. They actially get to sign their work. And when the designs go out of production… they don’t come back. Every scarf has a story:
http://www.wsj.com/articles/SB10001424127887323975004578499110750076242
How about a set of All Clad cookware? Macy’s FF sale should be here, and Bloomies is having theirs as we speak.
Yes to the cookware or other items to set up a kitchen. It can be so expensive setting up a new apartment - even buying all the spices, little gadgets and utensils needed. Getting quality products that would last a lifetime and probably outside of the budget of a recent grad would be a real treat for someone who enjoys cooking.
I agree on the All Clad, but I remember reading somewhere that the pieces in the sets are not the same quality as those sold individually.
Agree. A set does not have to come in a single box. OP can assemble “a set” from individual pieces (which is what I did for a wedding gift once).
I purchsed 10" All Clad stainless finish at Marshall’s last week for $39 on their clearance shelf.
I would go fo a le cruset --but then what color?
Le Cruset is too heavy for some of us. We have purchased and returned it several times. Sometimes Macy’s has a great sale on it and you can always return it or exchange it. Maybe a great knife set? I know Costco has some very nice ones, with a block to store them in. I know for cooks knives are VERY important.
If they live near a William Sonoma, maybe a gift card there? They have very nice things–at the store or online and she can select exactly what she wants and will fit her current lifetsyle.
OP, wants to give something personal - probably not a gift card to a retail store. Unless it’s paired with something else significant.
Le Cruset is heavy but this is a young’en graduating - she probably can handle it!!
In addition to the great suggestions of Le Creuset and All-Clad (or the cheaper but great quality knock-off Tramontina TriPly), other great gifts for a cook starting a kitchen are high quality cutting boards (John Boos), a hand turned salad bowl (etsy has some nice ones), a KitchenAid stand mixer, or a Cuisinart food processor. All would last a long time. I also agree that good quality knives would be a nice gift but sometimes people like to pick their own knives because of how they feel and fit in one’s hand. I’m a minimalist when it comes to kitchen gadgets since I dislike clutter but all these get constant use, something important if she’ll be working with a smaller space.
I do not cook often but a relative got me a set of nice knives for a graduation present. Still one of my favorite and most used gifts of all time.
If you do decide on a kitchen item think about adding a really cute apron and cookbook.
Does she have a KitchenAid mixer?
I like the gift card to Williams Sonoma. Then she is free to purchase mixer, coffee pot, bakeware, etc.
If she’s really into cooking, maybe a gift from Williams Sonoma, with explicit instructions that if she doesn’t like it she should return it and get something she does like. Does she do coffee drinks? If so, maybe an espresso machine? Maybe a nice pan that has a GC to local restaurant out of their price range?
Wow!! $300-$500??!! That’s a lot more than any of my relatives gave me for my college graduation.
Have you asked your son what her interests are and things she could use?
The main thing is to not stress about it. I am sure she will be very happy to not only get a gift from you but a pricey gift for that matter.
Longchamp tote bag.
^^A winner!!! 
I agree!
I’m going to wade in here…If you spend that much on her gift are her parents likely to do the same for your S? I’m just asking. I personally would not have felt comfortable getting that extravagant a gift from a boyfriend’s parents and part of the reason I would not have is that there is no universe in which my parents would have spent that much $ on a boyfriend’s gift, even adjusting the price for inflation.
I know two cases in which young men decided weeks before college graduation that they wanted to break up with their girlfriends. In both cases, their parents were stunned. In both cases, siblings of the young men got very, very upset about the break ups because they had really bonded with the young women they expected to be their future sisters-in-law.
So, personally, while I get that you really like her and THINK she is going to be part of your lives for years to come, I would be very hesitant to spend that sort of $ on a gift for her unless (a) you are very wealthy and would give that sort of gift to a young relative finishing college OR (b) you know her parents have or will give your S an equally pricey gift.
Just my two cents.