I really urge you not to feed your BP gerbils. Once they get started on them they can be impossible to switch over to more practical prey like rats.
As for her not eating. We could really use a lot more information. BPs can go off feed for any one of a thousand reasons, or for no reason at all.
How is your enclosure set up? How do you heat it? How do you measure your temps? Where is it located? A picture would be worth a thousand words as well.