How long does it take a fish to finish delivery of babies? She is a molly. I noticed two fry swimming around a day ago and haven't seen any more. Has she finished giving birth?
The fish birthing process can take 1 - 24 hours.
It sounds like your molly gave birth while you were away, but the rest of her offspring became food for the other fish.
It is unlikely that the baby fish will be able to survive around the other fish. If you would like to try to raise them, purchase some fry food and a breeding facility that lets water pass through, but not other fish. Catch and separate the baby fish into their new temporary home until they are big enough to be on their own.
Next time, you can put the expecting mother in the birthing chamber when she is near time, and remove her afterwards. Then you can raise all of her babies and watch them grow. It is a fun experience.