My mother-in-law-had a bad fall. She is hallucinating, has signs of delirium, and is not sleeping well. What can we do to help her?

She has incontinence. She is in our home now due to her fall. She has to be assisted to get up at night at least 5-8 times a night. She did have a bad head cut (probably a concussion) when she fell and bruises about every where. She is 88 yrs old. Only broke her nose as far as bones go. My question; Are we being to hopeful for her recovery after such a bad fall? It has been 3 weeks and I see no improvement other than brusies are gone. She also sleeps practically all day even though I get her up to bathroom/excercise/eat/walk/ I try to keep her awake during the day, but as soon as we are done with anything, she is right back to sleep. She sometimes looks pale or a little yellow. Her blood work came back fine from doctor. I am looking into UTI right now, but I do not see her getting any better and I can accept that because I am not only her D-I-N I am her full time care giver at this time for we thought she may get better, but with the delirium/hallucinations onset..I am not so sure she will ever get better from the trauma. Do elderly go down fast when they have such a bad fall and never really return to normal? She is only on Melatonin for sleep and a pain pill for her back and hip..but she has been on those, so this is not a big change in medicine regiman. She is on B/P med too then only on Vitimins..No big changes since fall. Please help me to understand the delirium/hallucinations if all else seems to be ok other than the fall and not in her own home. Thank you.