in my opinion, what will be important is her experience of "nursing care" (haha) at the hospital. She can maximise her chances of recovering quickly if she is well hydrated and well fed, gets good pain relief and good sleep, stays in hospital for as little time as poss, and dosen't get any infections.
if you are able to visit, there are some things you can do to help (which should be done by the nursing staff but hey ho)
get her to drink a lot (despite the fact it'll make her pee a lot - contrary to popular 88 year old belief this is a good thing)
make sure she is not malnourished (perhaps you could take in some things she likes)
get her to do deep breathing exercise and ankle exercises (ideally every hour while she's awake)
if she is on any regular medicines don't let them fiddle with them without good reason!