You need to be feeding her a high protien, quality diet right now as well as making sure she is getting ample amounts of calcium so that she can produce enough milk for her little ones. She should have a pretty ravenous diet right now. There is a recipe here on YT somewhere for an after whelping 'pudding' that you may want to try. I don't know it right off the top of my head, but a search should bring it up.
