Advice on the recovery from rear legs ACL surgery

My 2-year-old cat fell last night and tore both back legs ACL's with more damage possible. She is set to have surgery two days from now and I'm worried about her recovery at home. My main issues are: how long it will take her to walk, what kind of physical therapy I will need to do (over what time period and how much daily?), and the issue of going to the bathroom/litter box.
Since she tore both rear leg ACL's how in the world am I going to get her to squat and use the bathroom?? She has super long hair so I'm concerned about her hygiene as well. Any advice would be extremely helpful.