Will she eat fruit (apples, blueberries) they do the trick for my two.
Also, I have been feeding 1/4 teaspoon of Aloe Vera Gel that I bought at the health food store. It is drinkable and it is a natural laxative. Boy oh Boy does that make them poop. Mine went from pooping 2x a day to 4 or 5 times now....
But it has healthy benefits, so i am trying it out for a few months.