House modifications to adapt for senior citizen

My 80+ year old mother plans to move in with us in early 2023. I have three major projects planned to make her living more comfortable. She will have dedicated space for her room and bath.

1) Remodel her bathroom (replace tub with shower-stall) etc. to be safe

2) Install chair-lift since all our bedrooms are on the upper floor (she had both knee replacement several years ago) 

3) build a balcony so that she has open space and access to garden etc.

 

Which ones of above expenses can I count on as eligible modifications to get a tax break? Will this require prior authorization from doctors' office? I understand a balcony is too far-fetch, but chair-lift and bathroom are legit age-based requirements. Anyone with similar experience?