I'll be brief, but here are some initial thoughts.
1. Feed in the enclosure. Many snakes, especially shy ones, like BP's, get very stressed being moved somewhere to eat. Let her eat where she is comfortable.
2. Feed F/T if she took that in the past, unless you want a snake that eats live. It can difficult to get them to switch back to F/T. You might have to be persistent and/or try live, then pre-killed, etc. Not sure what to tell you here. BP's often fast, and will sometimes take live more readily when fasting, but that's not necessarily good unless you want to keep feeding live.
3. Open space equal insecurity for BP's. They want to stay hidden and not feel exposed. Another reason she may not eat.
4. How are you defrosting and offering you F/T food?
5. How much does she weigh and how old is she? Do you have pictures? She might be fine not eating for a while.
Any responses would be helpful and feel free to ask for clarification.
Good luck.