My concern is that she may be too young for traditional adult ACL surgery. A New York Times article earlier this year talked about the risks. Two passages:
The standard and effective treatment for such an injury in adults is surgery. But the operation poses a greater risk for children and adolescents who have not finished growing because it involves drilling into a growth plate, an area of still-developing tissue at the end of the leg bone.
And here's the scary part for growing teens:
But the standard A.C.L. repair operation, with its drilling into the growth plate, may cause permanent damage to the still-growing bones of young children. After drilling, surgeons replace the torn ligament with a tendon taken from elsewhere in the body, like the hamstring, or from a cadaver. But if the drilling damages a child’s growth plate, the leg bone will not develop normally.
That happened recently to a 14-year-old boy who was referred to Dr. Freddie H. Fu, an orthopedic surgeon at the University of Pittsburgh. A year after the operation, Dr. Fu said, the leg with the repair was bowed 20 degrees on one side and was shorter than the other leg.
“I had to go in on the other side and stop the growth,” Dr. Fu said. “Now, about six months later, the leg is still crooked. There still is a two-inch difference in length which I have to fix.” The boy, he said, “will be a little bit shorter” as a result, although both legs will be the same length.
I'm not a doctor, but I'm encouraging Brooke to show the article to her parents.
For us adult ACL recoverees, we can nod our heads along with this passage from the article (boldface added by me):
Every orthopedist is familiar with A.C.L. tears, but in adults. It is “the most common and most dreaded injury in professional sports,” Dr. Kocher said. The well-established operation to repair it often results in a full return to function. And doctors often recommend that adults have the operation because without the ligament the knee is not stable.