How to get an 88 year old female to bathe?

If she's of sound mind, try compromise. If that doesn't, nag and blackmail.

Thank you everyone for your wonderful advice! I am new to this and appreciate it very much. I do understand that there are a million reasons and all of them I truly understand. Thank you for your input! :)

When my father does not want to bathe, he is 250lbs, I heat up some wipes, or there are waterless foams that you can use. This helps until I can get him to shower.

My mother in law is resistant to her evening shower. Because of her congestive heart failure, she gets tired. This would happen if she had shower in am or pm. She loves her ice cream and I tell her after shower we will fix ice cream. It is really hard, I know. Maybe a shower chair would help her want to shower to be able to sit down.

What are her reasons? Maybe she feels too weak and thinks she can't shower. Maybe she's modest and isn't comfortable someone bathing her. You're right to not push or nag her.

Where are you? In her home? In a facility? Is this woman mobile? Can she stand in order to have a shower? Does she need a shower chair? Did someone else used to bathe her and if so, who? Have you been with her long enough to build trust? Is this woman a family member?

There ARE a million reasons why an elderly person doesn't want to shower. Does she have dementia? If not, just ask her why she doesn't want to shower. Sit down in a comfortable setting and ask her if she'd mind sharing with you her reasons for not wanting to shower.