It could be other things too. It took my snake two weeks to eat. Now she eats just fine in her 55 gal. I know its not a good comparison since every snake is different. It could be the kind of hide your using, or where you are placing the mouse when you feed. Maybe you're feeding her male mice and she prefers female, or colored mice vs white, live vs frozen. Remember if you make it smaller it will seem new to her, and give her a week to adjust. I would contain her to one side or the other, and i agree about quarantine with a new snake also. Find out what she was eating before. It's a good place to start.

Also, the pet store i bought my bp from fed her in a tub instead of her enclosure. Look into that too. Keep your head up, she'll eat when she's comfortable.