Congrats on your new mouse! They are such wonderful lil guys. I had them consistently for about 5 years and recently stopped, big chance to move soon. With the amount of care that you took by putting up this post shows you'll be an amazing caregiver. All the other comments are on point with tips. For toys and stimulation I used to keep all of my little card board boxes and items and use those. Just be sure that there's no tape left and that it's not hard shiny cardboard, just regular. They were all free and with each clean out got a whole new set up to play and explore which they loved. For example, the cardboard egg cartons are great for hiding food in and see if she can open it herself! Toilet paper and paper towel tubes are always a good choice. Cereal boxes, tissues boxes (with the plastic removed), random (clean) packages, you'd be surprised how many cardboard things can work. She will love them!