Get a live trap.


Is she just somewhere you can't reach? I've lost a few rats, but generally we had to take everything apart to get her.


Make sure there is no way for her to run away. Make sure she cant climb up the rack and just eat the food from there. Get a live trap and put in some stinky wet food. Then leave it alone all night.


I would personally not risk it and tear the room apart to get to her. She must be thirsty and dehydrated by now, she wont last very much longer being just weaned.