I have no experience with an ACL tear (thank heavens!), but you may want to check out these braces.....
http://www.woundwear.com/product3.cfm#
It looks like one of these would help stabilize her knee and may help with healing along with the injections. May also help prevent a double whammy by allowing that leg to bear weight better and not have the other knee blow out, too, from bearing more weight than it can handle. They're expensive ($345.00), but sounds like it could be really helpful for China.