When I see all the sites and all the costumes for adults, it looks like they are all for adults untill about 30 years old, with a nice body.
But I have adults, 30+, not so nice bodies after some pregnancies, a bit or more overweight, cup D but often more.
It is hard to find flattering balletcostumes for them. A leotard is not always a good basic for them.
Does anyone know sites with costumes for these kinds of bodies?

*Sigh* I know what you mean. I've been using River's Edge Dancewear for my adults. I don't know if they'd have what you're looking for, but they do have a good selection of plus-sized dancewear, and they were very helpful about my sizing questions on the phone last year.

River's Edge Dancewear

I am not sure what catalogs you have, but my body is far from perfect, and one of my colleagues is bigger than I (and I'm pushing 30 and she's 7 years older), and we have always found costumes that flattered our bodies. We have used Costume Gallery, Wolff-Fording, and Curtain call most recently.

We also have to costume bigger dancers, and whether or not a dancer is older or younger than 30, they still deserve costumes that will flatter their bodies...I think that if you look in the right places you can find things. Do you not have any younger students with less than perfect bodies?

^Yes, I have children with less perfect bodies, but they are still a minority (1% of my students is overweight, I'm not in the USA).

I'm faced with the same challenge this year. I myself no longer have a traditonal dancers body but I still need to costume a group with a WIDE varity of sizes. I'm looking at the Art Stone catalog. They have many costumes that to up to 2x and 3x sizes.

Have you tried Dance Depot (www.dancedepot.co.uk). They are distributors for Leos Costumes, which has recital costumes in XL. They also have some of own stuff in dancewear catalogue? Good luck!