Hello rob...
A suggestion you may consider: Females will hold fry until they feel conditions are optimum for fry survival. The tank chemistry must be stable. A 10 gallon tank is difficult to keep clean even for an experienced tank keeper. The water properties can "go south" in just a few hours, because there isn't enough water to dilute toxins.
I'd suggest a larger than normal water change and make the new, treated tap water a bit warmer than normal. I've found with my Fancy Guppies that females close to dropping their fry, just need a flush of warm, pure water to make them feel like conditions are right.
Just a thought.
B