Just so we're clear she hasn't lost any weight. So whats the problem? I've got a hatching that has only eaten once since she hatched, If they are stressed or there is something a miss with her environment they wont feed. I just looked at the rack you're using and even cut in half it's bigger than even I would try and start a new baby out in. My suggestion use a smaller tub (darker tub), offer a hide, and forget about feeding for at least 7-10 days. Don't offer, don't look, don't take pics, open the tub to makes sure its still alive at night, check water. Other than that nothing, then after ten days offer a smaller (live) meal than what you were and leave it over night mice and rats that small pose no threat to your snake so don't worry.