Do I have to worry?

[hissykisses]

Hello!

So my BP Peggy doesn't want to eat. I got her on October 1st, she's supposed to be about 1 year old and currently weighs 530grams. I've tried feeding her 4 times since I got her, but she keeps ignoring the food. I've tried with f/t big mice, a medium rat and even a small rat because she seemed interested in the rat the most, but she doesn't eat. Yesterday I tried with a mouse again and she did strike, but that was about it. After that she curled up and ignored it completely. I left it in her tank over night, but it was still there in the morning. She has been fed f/t before so that can't be the problem.
I got the impression that even the big mouse scared her (it was about 38grams, so not that huge, really)
Since I got her she lost 20grams and that's not much so I am not too worried at the moment, but I wonder if I should start to worry if she keeps refusing to eat. I've heard about BP's being picky eaters and all and also that they sometimes won't eat for months, but I would prefer if she would eat sooner rather than later.
I would try with living prey, but if she doesn't eat the animal I have no means to keep it somewhere here at home (and also don't want to) and I wouldn't dare to feed it to one of my other snakes in case they would refuse the f/t afterwards...
What to do?