My mouse just had surgery?

Very sweet :). I hope all goes well which it sounds as if it will. Yes you can give her a small bit of well cooked chicken or any meat really also scrambled or mushed boiled eggs work very well and even high protein dog treats. All these are high protein and will build her energy up and help her gain weight (also if she likes sweets peanut-butter will defiantly fatten her up but don't give her much) but pleas remember to take all foods that call spoil such as meat and eggs out of her cage within 6 hours. Sense she is 8 weeks old she should be fine with any food. I suggest a warm towel (if you think she is cold) if shes not cold you may just make her more uncomfortable. I really hope all goes well :)