The pictures are a bit blurry but she does look pregnant! From experience - when she looks like she's going to absolutely BURST she's getting close to having the fry. They grow quite a bit in pregnancy. You don't have to separate them, sometimes it causes more stress than leaving them together. In the wild they wouldn't be separated.
If you want the fry to survive try putting in some plants - I prefer the floating fake ones. Easy to put in/take out and some fry are bound to end up lunch but if they all survived you'd be wishing you didn't save them all. It's great to have lots of new babies swimming around (especially platys! they're adorable) but unless your LFS wants them - they're impossible to get rid of.
Congrats!
