Hi. I don't think you have much to worry about based on the information you provided. What is her weight like? Does she seem excessively skinny? As long as her weight is fine I wouldn't worry just yet. Keep offering her a meal once every week or so.

Are you only trying to feed her Frozen Thawed now or have you offered live? Between moving into a new home, switching to F/T and the fact that it is winter, there is a good chance that she has just gone off food for a while.

I currently have 2 Ball Pythons at the moment that haven't eaten in 2-3 months. Many of them will do this during the winter months.

Adults can go off food for quite some time but Juveniles will obviously need to feed sooner. Have you tried contacting the breeder? He may be able to supply you with a live Rat to try?

https://www.reptilerange.com/ball-python-care-sheet/