Bridesmaids dress ASAP

So my MOH was pregnant when the other girls purchased their dresses and she just had twins a few weeks ago!!!! They are the cutest little peanuts. Anyway she's settled in and ready to go dress shopping this weekend, but the initial dress she wanted from David's Bridal won't get here in time. Do you guys have any suggestions on other places we can go where can can get dresses off the rack or where it doesn't take as long to order. We can order online with expedited shipping, but she needs to try dresses on she's not sure what size she is. I'm in Boston FYI (GO PATS)