Everyone is giving good advice and I second all of it. She will catch on eventaully. I too, like Rachel didn't think Keegan would EVER figger it out either!!! It took her until she was 5 mos. She has had a couple accidents since then. Like when she came home from being spayed and one day this summer when mom and I were cleaning and not paying attention to her.
Keegan was the opposite, she figgered out the poop thing within weeks. I got her like Middle of November and by the beginning of Dec she was pooping outside, but NOT peeing! When my Christmas tree was up I did find some underneath it, but I figgered she might have thought she was outside with the tree and all!!! My neighbor has a GR and a pomerian (and now a GR mix) and she told me that her 2 didn't get it until they were 5 mos. And it was like Clockwork! I know your friends probably don't want to hear that tho!!
But when the puppy does go outside praise her like crazy and I give treats. (one) And if you do catch her going in the house, I was told to like "shame" her I would always say "Keegan, shame on you! etc" and she would bow her head and look at me. Then she figgered it out!! It is such a relief when they do!!! GOOD LUCK and keep us posted!