It is normal here for family members to camp in the hospital. If the mum has no other family support I suggest provide a small roll up mattress, spare clothes or do laundry, meals, and moral support. Hope there is a good outcome for all.
Go a different visa route. Come as tourist get 30 day visa exempt entry. Apply for 90 day O Visa in country. Extend that by 12 months in country. Over 50 and have finance.
As suggested but also take the walk up to Hellfire Pass. Not too far but worth the effort. I also went to the Jeath Museum across a lane from the Commonwealth Cemetery