Couple of things with a new baby ball:
Did you get her from a breeder or a pet store?
Do you know exactly what she was eating before, rat or mice, frozen or live?
This is going to sound harsh, but after you get the cage changed around, ZERO handling for a full 7 days. Just check her water and make sure the temps are good, but do not handle her. Offer her first meal at the end of the 7 day no handling period. For the first meal, offer exactly what she has eaten before. If it was live, you need to offer live. After a few successful meals , then you can try to change to frozen thawed.
If you follow those steps, there should be no issues with feeding.
Is there any way you can snap a picture of your cage set up? Big open aquariums are really scary to baby BPs. A less confident and fearful snake may need extra hides or ground cover. Toss in some paper towel rolls, or fake plants.
They are shy and secretive snakes. An additional way to help is covering a few sides of the tank. You can use aquarium backgrounds, towels, or simply dark colored paper. This does not have to stay up forever. Cover three sides and leave one open. Over time (months) take the paper down one side at a time.