It's very possible she aborted. Females who are close don't like breeders or like to be moved. Sometimes the fry will stay still for a bit and viable fry sometimes have the very bloated look when they are a bit early and are still living off their yolk sack. It may take a few days for that to disappear. I have had the best luck especially with platy, to let them birth in their original tank and scoop the fry as soon as you see it. When I started out and tried to move the moms before birth I often ended up with either no fry or a dead mom. I have found lots of foliage in the back corner where the heater is and some moss balls on the bottom gives great coverage for the fry and yields fat healthy fry to boot. Just ro;; away the moss balls and you will find the little guys under them. I hope the little guys make it...
Michelle