Are you sure this is a female?
Looking at your pix, I see something that says it is a male -- do you feed it well? If the fish looks like that today, then my guess, it is a male. Females are much more rotund, with what looks like a black point in the rear when they are about to have their babies. The other thing is, if this one is from balloon-belly mollies, like my original molly, you will think it is pregnant and then discover it is a MALE. I waited a month and a half looking for babies and nothing. Then did some research and found it was a male BB, so I was flummoxed.
If it has a gonopodium, a long slit-type of bottom fin instead of a rounded set of fins, it is a male. Look up males, see the difference in their bottom shape. If it is a female and does have a few babies, then she is young and probably will get more rotund on the next time. Also, females can hold babies for a little while if stressed, and can wait for months before the next time to have babies, if they want. They don't need a male for every fertilization, as they can hold sperm for a long time.
Lastly if she is in a fry tank, with fry in there with her, then she can help herself to the fry as a snack. I would make sure you put her back in the main tank and leave the fry there; it is easy to scoop up the fry, if she actually has them in main tank.
