isn't the mother just providing the nourishment for the fetus to grow inside her? and the fetus itself, takes the nourishment, and actually producing the eggs inside itself?

So technically I don't think we can say the grandma is making the eggs directly, but has assisted in the fetus' creation, and then provided the nutrients/environment for the egg creation that the fetus itself makes (which yes, can influence things w/ the generational trauma science coming out...).