If I have a refusal, I'll leave it in overnight. I've had my pin take it over the night sometimes, other times he leaves it altogether. The month thing is just a generalization. If she starts looking really bad in a week, it might be time to take action. Or who knows, she might go for 2 months without losing a gram. It's different for all snakes that go off feed. You just need to use your best judgement. But you've only had her for a day, correct? No need to start freaking out just yet