You could deworm to see if that helps. Ime, when they lose their legs like that, often its something reproductive going on. Cancer, EYP, etc.
Curling of the toes can often just be a response to being turned over, sometimes if they are curling while she's laying down, possibly a pain response or could just be flexing the feet, hard to know.
For deworming, Fenbendazole is a good choice. Safeguard Liquid Goat dewormer (10%) is what I'd use. Dose is 0.23ml per pound of weight given orally once daily for 5days in a row.