My Bridesmaid gained 20 lbs and cannot fit her dress my wedding is in 6 weeks

I agree with Sarah that I'd have her check on Poshmark, Mercari, Ebay, etc. to see if somebody is selling the dress, as well as take it to a private seamstress to see if there is anything that can be done. I definitely wouldn't demote her because she can no longer fit in the dress. She probably feels humiliated enough about the weight gain. If she exhausts all her options, then I'd have her get another dress which looks as similar as she can find.

Davids bridal should allow her to exchange it to fit her size

Could you have a corset back sewn in with a piece of pink material under it?

Maybe a jacket or sweater to cover the back

Could she add a bolo or a cardigan of some sort in the same color? Or like a shawl?

Have you looked up the dress online? I know sometimes if you search a certain item you find specific locations that it is being carried. Beautiful dress though. Perhaps Amazon will have something in a similar color you can get fast.

I had the same thing happen to me. One of my bridesmaids gained a good amount of weight due to health problems. She thought she could lose it in time for my wedding, but no-go. The dress was a David's Bridal one, and they had discontinued the navy blue one. (My bridesmaids were among the last people to buy what they had left.) As in your case, my friend took it to multiple tailors trying to have it altered, but they would have had to take the entire dress apart and put it back together, and she didn't have the time or money for that. I was a little miffed at first, more so because she didn't tell me until the week before the wedding, and she even said I could kick her out of the wedding if I wanted. I told her she was crazy and that dresses are replaceable, but friends aren't. Thankfully, she had another dress that was very similar, so she took the rhinestone belt that had come with the bridesmaid dress and put it on her dress. She looked beautiful, and more importantly, she was still in my wedding where she belonged. If I were you, I'd start looking now for something as similar to the original dress as possible. Check Ebay, Amazon, and any other resale shops you might know. Also check the sale section of the David's Bridal website. In addition, ask yourself what's most important in the end: if all your ladies are wearing the exact same dress, or that all the people you asked, making them the most important people who you trusted most, all be there on your special day. Good luck whatever happens!

This is what I did for a friends wedding when my first seamstress wrote down the wrong measurement and took it in 4 inches too many! Luckily it hadnt been hemmed so I went to another alterations place and they used the extra length from the bottom to create the panel. No one noticed and the dress still looked beautiful

If the dress hasnt been hemmed yet they can take the extra length from the bottom and create a panel in the back. I had something similar happen due to a seamstress error where they took my dress in 4 inches too many! Luckily they hadnt hemmed yet and another alterations place made the panel. No one noticed and the dress was beautiful.