[observer]

For a while, at least, you are going to have to go outside with her and do the housebreaking sequence in the back yard... happy dance and praise when she does her business and all. She will figure it out once she has spent enough time out there that the back yard is as familiar to her as the front.

I can't say you will always have to be with her when she is outside, as I don't do that myself. (I would think differently with a youngster like yours, though. I would not leave her alone outside).