It`s not unusual for first time spawners to have a low survival rate. If the yolk sacks are gone they must be mobile, especially if they are eating. Free swimming does not means they are all over the tank, just that their head thread is gone. Mom and Dad may keep them in a tight group for a couple days as they learn how to swim and hunt for food.
Sit back and enjoy the show. Make sure if they loose the fry that the male does`nt kill the female and give them a while to spawn again. They will figure it out.