I too went thru the same thing with Sully at about that age.
But now he is 10mo and we only had a short string of accidents at about 6-7 mo. but none since! None! It's great!
I think when they're learning to "hold it" ...it takes them longer to realize that when they feel they need to poop, they don't have to squat and do it RIGHT THEN.
I noticed that w/ Sully b/c even if he'd just been out, he'd poop whenever he felt that he had to, and couldn't wait, but now he can. So there's hope!
My best advice is to be consistent about letting your dog know that it's NOT ok for them to go in the house, and be patient. As long as your dog knows it's not acceptable, she will work harder to please you next time. And one day you'll hopefully find yourself with a 100% housebroken dog, yay!