I'm so sorry your mum's unwell 
As PP said, a luxury item like a shawl, scarf or a blanket would be something she can enjoy without effort
I have an aroma diffuser from Oliver Bonas and have purchased one for a relative for christmas- they're wonderful and very soothing especially with lavender scents to help with sleep.
It may sound silly but fairy lights or a salt lamp might be helpful as a night light for her or to have on in the evenings, especially if she needs care or checks in the night it means the lights don't all need to be turned on.
Some pamper items like hand cream, nail polish, face masks and face wipes might help her feel a bit fresher and ready for visitors.
Fresh flowers or houseplants by the window help if she's stuck inside.
Bath or shower products if she can manage it- L'occitane and Neal's Yard have some lovely bath oils that will help if she has dry or sore skin. If she can't manage anything but bed baths they can be used in a bowl of warm water for just her hands and arms.
You can get tray/desk things on wheels that slide over the bed- she might find those helpful for meals or any activities she can manage. She could keep snacks and drinks on it too if that's more accessible. www.aids4mobility.co.uk/over-bed-table-with-castors.html this is just an example.
We're here if you need any more ideas or advice x