Is she round or more triangular shaped? If she's round she should be fine without food for a while.

How long are you waiting between feeding attempts. It sounds like she's still stressed since she's acting scared of the rat. This may be due to offering her food too frequently (which 6-8 times in the last 3-4 weeks is far to often). If she refuses food, don't offer food for an entire week. The next week offer food again.

Good job on leaving her alone for now and leaving her in her enclosure for feeding attempts. That should definitely reduce stress.

Usually I'd suggest offering live since most Ball Pythons will readily accept live when refusing F/T, but it sounds to me like she's just stressed, so live wouldn't help that issue at all. A live rat would probably just cause additional stress.