Sorry to hear that. For what it’s worth I tore acl/mcl 18 years ago and have had no trouble since the original surgery. I went with cadaver tendon for replacement rather than grafting. It’s a long recovery period with regular rehab routine that consists of mostly getting flexibility and strength back. I don’t know her age but if she commits to the therapy/rehab she will be fine. Good luck.
Then she’ll embrace the rehab. She may even comeback stronger. Also, I know several other athletes that have had same injury and all agree to ditch the leg braces as soon as doc signs off on it. It can become a crutch and prevent full recovery. I’m sure you’ll do your research if you are here.