Cat Problem

Recently I have noticed That my Female who had just gave birth recently had started getting diareah like ayellowish kind.. I'm not sure if i should be worried or just leave her alone for a while, because she seems to be so picky these days... (even with a little bit of litter on the floor she starts complaining)

Should i feed her something different? I feed her Purina cat chow, and meow mix pouches, somestimes treats aswell...

thanks
Steph