Daughter's concern for my health

If I was your daughter I would want to know, she may very well find it upsetting but she may be more upset if she finds out later and realises you didn’t tell her.
Also will make your life so much easier when she is able to accommodate your health issues.

Does your GP or hospital have any information leaflets about your condition? You could leave them somewhere in your home where your daughter is bound to see them and this might prompt a conversation about your mobility problems. Some people just don't understand medical issues or appreciate how much pain others are in so you may have to be up front about it.