What jball said. She is at 'that weight'. Between 1200 and 1500 grams, females OFTEN take the winter off from eating. If that's what she's up to, it's probably hormonal, and she will start up eating in the late spring around the time females are laying eggs.

I've had picky eater mouser girls go through this adolescent fast, and then pick up on the other side eating rats like they've never refused a meal.
If that's what it is, she should eat heartily for you next summer, and be ready to breed the following fall.