Sounds like she's hungry. Mice are too small for a 1.5 year old who seems relatively thick. If you can get a scale and get a weight in grams, that would be helpful in narrowing down what you should be feeding her and how often.
If not, you'll have to eyeball it. She can definitely take some rats now. A rat about as big around as she is wide at her widest part is what you're looking for. One meal like that a week should be good for now and help fill her up a bit. If you can't do rats for some reason, you'll have to do multiple mice.