Will isn't this the snake that was just dropped, possibly stepped on that you were upset about? After that kind of experience only days ago it's not really surprising the snake would refuse.

Let's just work the problem, refusal isn't the problem, it's a symptom of other problems affecting this snake's willingness to feed.

First off is husbandry. Please post clear pics or describe the setup your 4 month old BP is in (include information about type and size of enclosure, substrate, hides, heating source, etc.). Please list the temps on both cool and warm side, plus humidity readings. Please describe in detail the method you are using to feed as well as the prey offered. When you say "fuzzy" or "pink" you need to be specific about whether this is a rat or mouse and whether it's being offered live, frozen/thawed or pre-killed.

Next would be known feeding history for this snake. It's 4 months old, you've had it a couple of weeks so who had it before you, what did they feed it and in what manner was it fed?

Next is handling. Obviously this snake has bee "handled" when it was removed from it's tank by your little sister and let loose. What other handling experiences has this snake had in the period since you've owned it. What is the general area of the house the snake's tank/tub is in (bedroom, livingroom, etc.)

Lastly is health. Depending on where this young snake came from you may need to get a vet check done with a fecal float included to check for internal parasites.

It's a lot of information to ask you to post but it's all very relevant stuff. With more information from you we may be able to give you some advice to help with this situation. The important thing is to just take a breath, don't panic and work the issues one by one. You aren't the first with a non-eating BP and most times it can be dealt with, with adjustments to housing, handling, lessening of stress on the snake and changes to the feeding routine (all that assuming the snake is healthy in the first place).

Please do NOT consider a forced or assisted feeding at this point. That sort of thing should only be done, as far as I'm concerned, under the advise and direction of a good herp vet or a VERY experienced breeder.