D.M.
Every child develops and learns, weather we like it or not on their own terms, but one thing to try if it is possible for you is to along with teaching her at home, put her in a day program for a couple hours a day a few days a week and let her be around other children who are "doing the same thing" (going to potty) and I bet she may want to do it to. With a new baby it is going to be hard to get her not to want to be the baby to but positive reinforcement and persistence will pay off. Good luck!