Is this the right blue for the OP’s friend?:
https://www.theknot.com/fashion/m160053-jasmine-black-label-mother-of-the-bride-dress
This one looks like it may be a flattering fit:
https://www.theknot.com/fashion/212811-social-occasions-by-mon-cheri-mother-of-the-bride-dress
Thats very pretty, sooz, and would fit my shape, but if thats for me and not the OPs friend, there is no store within 100 mi that carries it 
That lace overlay seems to be the “in” thing in formal dresses this year.
http://shop.nordstrom.com/s/tadashi-shoji-bonded-lace-fit-flare-dress/3926629
http://www.tadashishoji.com/acz1345l-nv-iv-contrast-lace-waist-gown
http://www.tadashishoji.com/ans1954m-nvpet-mermaid-embroidered-tulle-sleeveless-flare-skirt-dress
Jym…I already love YOUR dress. My suggestions here have been for OP’s friend!
So, here’s one that may have a flattering fit and could be hemmed to be a knee length dress in the right color, maybe?:
http://www.newyorkdress.com/Morrell_Maxie/14772.html
Another that could be hemmed to cocktail dress:
http://www.newyorkdress.com/Morrell_Maxie/14857.html
Another A-line gown that could be shortened:
http://www.newyorkdress.com/La_Femme/19922.html
PS, I shop online mostly and so the fact it isn’t in a local store would be OK by me if returnable.
Thanks, sooz. My dress is not a for sure, so am still “shopping” and appreciate all help. This thread was perfect, with lots of tips.
This is pretty and is actually periwinkle and would work shortened to cocktail dress length:
Another one that is periwinkle but would need to be shortened:
Would the MOB consider Royal Blue since that is what bridesmaids are wearing? If so, there’s this:
http://www.terijon.com/shop/cocktail-dresses/royal-blue-boatneck-lace-cocktail-dress/pid/1946/81#P=F
When you mentioned YELLOW in the first post, I have to admit, I have seen VERY little in yellow but finally just found one:
http://www.terijon.com/shop/print-it/taffeta-drop-waist-dress/pid/2142/9#P=F
Very few of the MOB dress models look like they’ve even given birth, let alone are old enough to have a child getting married.
So many lovely dresses! I’m glad as “only” a guest, I can wear slacks and look for a fabulous top instead. My niece is having an August wedding, and my one of my best friends has her eldest D getting married in Aug/Sept as well. I guess I have an excuse to shop. Maybe I’ll find something stunning on my trip out of country–something to keep an eye out for. 
I’m mostly more comfortable in slacks, since I have quite a few scars on my legs and HATE wearing stockings or hose or anything similar.
I know this isn’t the most fashion forward choice, but you would be surprised how totally forgiving and flattering the Tadashi Shoji stretch lace dresses are. They are designed to give the illusion of form fitting while totally flattering the middle-aged form. There are s million different styles and colors. Here are a couple:
Don’t be put off by how form-fitting they area in the pics! They are almost universally flattering.
As far as length, I think to-the-knee or just below is almost always more flattering than tea length.
^Except for those of us with tree trunk lower legs. Alas.
You guys are great. I’ll pass along the additional suggestions. She expressed gratitude for the first bunch of suggestions.
I just hope that if/when the time comes for me (my daughter is about as far from getting married as one can be – still waiting for the first boyfriend) – that you’re all still here for me to consult with.
What nottelling said! Tadashi offers a large selection of plus sized dresses, and they are quite flattering. Also, RL faux wrap dresses are worth looking into even though they look fitted in the photos.
For example:
http://m.shop.nordstrom.com/s/tadashi-shoji-embroidered-lace-sheath-dress-plus-size/3616102
and
http://m.shop.nordstrom.com/s/lauren-ralph-lauren-dot-print-faux-wrap-jersey-dress-plus-size/3992348
This thread made me look. Was at Nordstrom today and I saw a number of the dresses in this thread including Jym626’s dress. I don’t think the dress is short for a woman over 50.
I am not sure I like the Komarov dresses. I think they might be an awkward length but the fabric felt very comfortable.
If a dress is too short, remember it’s quite simple for a tailor/seamstress to add a band of complementing fabric. You could do a lacy ruffle or a series of colored bands, or a handkerchief hem…
Also, when shopping online, take into account that most models are 5’ 10" or taller. Extra 4 inches makes a difference for me, a 5’ 6" -er. 
thats a thought, dmd77
The dress you are considering, jym, does NOT look too short to me. First, I think that length is in style currently. Second, you are petite and it likely isn’t that short on you.
I’m over 50 and wear dresses that are above-the-knee. I used to wear longer ones but feel the current styles are shorter and many below-the-knee dresses look either outdated or too much of an “older” look.