I agree with Marty. Maybe give the nursing mothers lesser points, or have them take time out to nurse, change or bathe babies so that they are doing less than others. Or have a "day care" set up where some nursing mothers take care of the tribe's babies, with the nursing moms coming in now and then to nurse, but otherwise contributing to the tribe's welfare.

It would also be nice for the kids to do tasks as they've been doing, like finding the mushrooms, starting at an earlier age but also continuing to do it from time to time on their own. Even in the most primitive tribes kids start working earlier doing small tasks for the greater good of the tribe. And maybe have them do tasks randomly from time to time, once they've been taught to do it.