It's possible that your sweet-beep could be doing a normal response to winter & maturity by going off feed. Snakes respond not only to temperatures but also
to shorter day-lengths, but also it might be related to being in a new household. I'm also assuming you aren't handling...that plus a change of household can
also put a snake off of eating. Sounds like you've got her set up correctly...I'm curious, how often her former owner was feeding her? Weekly sounds like a
lot for a 2.5 year-old snake...so maybe THAT's actually what put her off eating...too much food. If it's not a "winter-response", maybe it's a "too much food"
reaction, lol. Either way, you'll figure it out. Sounds like you have the right size food, but I'd say you've been feeding too often for her age. Snakes are great
teachers of patience & they make "detectives" of us all.

(Even if her previous owner fed her once a week, it's also possible that he was feeding smaller
prey items...not all sources label prey sizes the same way.)