hey, welcome. did her eyes turn hazy at some point/is her belly pink? That indicates the start of a shed cycle. If not, then there is some other reason why she isn't eating.
1. do you know if it was a wild-caught snake or a captive-bred snake? many wcs have parasites and most experience a lot of feeding problems. Whenever you get a new pet, you should take it to the vet for a checkup, or at least have a fecal sample analyzed. This way, you'll be able to tell if she's got internal parasites.
2. check the temperatures in your tank. The hot side of a bps tank should be around 90-95F during the day, with the cool side at around 80. If it's too cold, your snake won't eat.
3. how often do you offer her food? if you offer every day or every other day, this will stress the snake out and she won't eat. wait until she's really active moving around her cage before you offer, and wait 4-5 days between attempts. DO NOT HANDLE HER UNTIL TWO DAYS AFTER SHE'S EATEN. Snakes won't eat if they're handled too often, either.
4. what kind of food are you offering? mice? if so, try switching to rats. rats? if so, try switching to mice. Are you offering frozen food or fresh killed or live (HOPEFULLY not live, esp. for a first time snake owner)? If you feed frozen, how are you thawing out the food?
5. How do you feed her? I found that when my bp refused its first feeding, the cause was my own improper technique. I touched the rat to its body, which scared it, instead of holding it very still in front of its head. I also moved it from it's home tank, which also freaked it out.
BPs are often very, very picky eaters. Before you worry about techniques to make snakes eat (braining, dipping in chicken broth, scenting), check to make sure you've got the basics covered.