BPs can go on fasts where they won't eat upwards to months. Just sounds like that's what's happening to your ball python. Heard some stories of even corn snakes not choosing to eat for 5+ months and being perfectly healthy. Just keep a eye on her weight and appearance. It could be a husbandry thing but considering she was eating perfectly for you it's more or less unlikely unless you changed something recently. To be on the safe side check out her temps and make sure they're consistent as it's getting a bit colder.