We get volunteers at work - but for whatever reason, regulations mean they can do very, very little short of sitting chatting with the patients. I will never forget one young chap, I think he was still in his last year of school, who sat with a patient for 45 minutes talking with her. I ended up with a lump in my throat when I over heard him saying he wished she could be his grandma.
I would encourage her to sort of leap in if she can. It's hard but you have to just throw yourself in. People appreciate it more than someone following you or sitting waiting to be told what to do - try to find what needs to be done and go and do it, within reason.
Talk to the HCAs, we usually have a little more time to talk and do more basic tasks that volunteers can sometimes get involved in.
She could -
Offer patients magazines, books, DVDs, etc depending in what's available
Encourage patients to swap existing stuff above.
Help with hair drying and styling (we have a box of rollers, tongs etc for this purpose)
Help with putting on make up etc
Sort out the TV, radio.
Give out towels, extra blankets as necessary.
Talk to the patients - there are few things as valuable as someone who will sit and chat. If it's an elderly patient with dementia, gently encourage talking about their childhood. Some patients will come with photographs, have a look at them. Ask about school, grandchildren, pets, holidays. I couldn't have been more thankful to that young man that stopped to talk - that gesture of his was wonderful.
Get the board games out of the cupboard - find someone without a visitor, offer them a pack of cards and take it from there.
Offer to support relatives - many times I have ended up chatting with frightened or even bored children. I've even carried a baby around the ward so Mum could talk with her husband. Show kids where the toys are, get them a drink of juice.
Learn about specific routines and ward procedures - where does the dirty linen go? Can she take it to the disposal room to save the nurses time? Can she help unload stocks, tidy drugs cupboards?
Obviously she should steer clear of anything involving dressings, intimate care, medication, paperwork and signing documents. She should never offer to do anything involving moving and handling - even just supporting a patient with walking to the loo. She should also check the hospital policy on assisting with eating and drinking - we don't allow any volunteers to assist with either, as a rule, because they won't know of the patient's needs (puréed diet, etc). But she can certainly do a lot of very useful things!