I'm almost the exact same size as your daughter, and I am always worried about modesty with swimsuits. I've found that AE, hollister, etc. just don't really make swimsuits for curvy girls. But the most important thing to look for is a good style for support. Halters, bandeaus, and underwire styles are best. String styles are awful, and the balconette type are really bad, too. Gap, J. Crew, and Old Navy carry lots of good options. VS is hit or miss--some of theirs are great, but others are awful. If you have the money, you should look at Betsey Johnson suits, too. They're adorable and supportive. You could also take her to a store like Everything But Water, so she can try on lots of options by various designers.