Sorry about your grandmother! To be honest, recovering from a broken hip is difficult for any elder. Research has shown that up to half of people who fracture their hip
do not survive a year after the fracture because it is so tough for them to recover. Remember at her age, the surgery itself is very risky. The major risks of surgery include infection, blood clots, and bleeding. Prime sources of infection are the surgical site, the urinary tract, and post-operative pneumonia. It is not easy for anyone, let along someone who is over one hundred years of age.
If she survives the post-surgical period, then she has heal and recover after the surgery. At her advanced age, this will take more than 6 months. Things that will improve her chances of survival include participating in rehabilitation and eating well so that she can heal and get stronger.
The bottom line is that her chances of survival really depend on how strong she is. Good luck!