Glad to hear she's doing better.
On the topic of stretches, if you go slow and gentle you'll feel if there's any resistance. I only very gently and slowly pushed and pulled a few millimeters beyond the initial resistance with my lamb's knees, but the injury here is different. Massaging is almost as important as stretching. I wouldn't do too many repetitions or do it too many times a day. Helping her stand and move are about the most important aids to her healing.
On the topic of mess in the house, you may be surprised but you can house train her. It will get harder as she gets older since they poop a lot more the older they get, and given that she's a special needs baby it may be better to just use a nappy or harness for collecting the poop and pee, but it is possible to housetrain them. How you do it depends on how you and your animal interact and what they respond to as an individual. It may be excess stress at this point. I didn't housetrain my lamb to begin with but now she knows where to pee and poop.
Best wishes.