They are only on hoppers for maybe three feedings then adult mice. Go with an adult mouse that is 10% of her body weight. Hoppers are too small. When you get them home leave them alone for a minimum of a week to settle in and de-stress. Once you have three consecutive feedings you can start to hold.

And it it is fine to wait until wed or Thursday. She isn't going to lose weight in three days. She will just be a little extra hungry.

What is her weight?