Juvvie Guppies
Hello KK...
I don't separate my pregnant females from the rest of my Guppies. It proves stressful. Anyway, your fry can go in the main tank after a week or so. You should be feeding a little frozen food every few hours and the little ones will grow quickly.
I would feed the fish in the main tank a little more and a little more often. It's been my experience with "Livebearers", that well fed adults show little or no interest in the fry.
Hopefully, you have some floating stem plants in the tank. Fish in general feel more comfortable in more heavily planted tanks.
Just a suggestion.
B