I'm 5' 2", 90 lbs, small chested, and usually fit into a small.
I got a S in charcoal/yellow; the colors are great, and the leotard is comfortable and durable. My beef with it is that the straps are kind of long and the front dips pretty low, and until I'm warm enough that I'm sweating and the leotard sticks to me, I'm constantly in fear of cambres that threaten to expose me. I probably should have ordered a P.
I got this leotard recently, and it was on sale (I had wanted it for a long time) and I was glad I got it! Other reviews said that this leotard ran small, however a P(petite) fit me just fine (5', small chested, skinny) however the leotard had longer straps so it came low, but I just sewed them and now its fine, also the back design is GORGEOUS! my only minor complaint would be that it is a bit sheer( i got the charcoal) even for small busted people, and also if y arch your back (or do an arabesque) the back straps are kinda "loose" (hard to explain) but overall I love this leo!