Pregnant lionesses actively hunt with the rest of the pride until the last few days when they rest in a secluded place to give birth and take care of the cubs for the next 1-2 months.

So maybe you should make it so that pregnant lionesses can hunt until the 3rd day. And maybe if you have a pregnant lioness hunting, she should get extra EXP for her effort. Also maybe you should make it so that you can give nesting material to the lioness for her to use on the 3rd day.