Yes, I agree that BP2 is overweight. And your PM description of her feeding style (only coiling with her neck because her midsection is too girthy) is a good & accurate observation. Unfortunately snakes do not do weight-reduction diets very well- it's very hard to get them to lose the fat & it often shortens their lifespan (from things like fatty liver disease etc).
Your goal should be not allowing her to get even more overweight- she still needs to eat, but gradually lengthen the time between meals & keep the meals small. Do not feed any rodents (either rats or mice) that are "old breeders" as they're high fat, & not what she should be eating. By the same token, rodents that are young (just weaned or younger) are also high-fat, so choose the smallest lean adult rodents to feed her- if she'll take mice, that might be preferable since the adults are smaller than rats by far, but BPs often have preferences & accept only one or the other.
Were you planning to breed these snakes?