House Trained Puppy Started Pooping Inside?

We have a 10 month old Pit/American Terrier mix that has been potty trained to go outside since she was 3-4 months old. She has recently started pooping in the house sometimes right after coming inside. The only thing that has changed, is that in the last 2 weeks she is afraid to go outside alone. I will go out with her to do her business and even after going outside she might go inside again. Help!