I agree that routine and consistency is a big help and a consistent feeding schedule. She's still very young. If she goes even sometimes on the pee pee pads.....pat yourself on the back!
Dogs are like children in that they thrive on routine and consistency. Our adult dogs do really well if we stay on routine but if we get off of it they will surely have an accident in the house. Keep at it and she will get it. I read somewhere a while back, I think an article in our local newspaper, that puppies bowel system and urinary tract aren't fully developed enough to "hold it" or go potty on demand until they are somewhere in the neighborhood of six months old and that patience is key.