She is 92, never worn one, she will forget she has them in, shower and ruin them. It’s just a money pit.
You may want to consider getting her an iPhone with a hearing aid app for 6 months first so she gets used to taking them out before she showers. The new iPhones are waterproof, and air pods are cheap and pretty water resistant. It’s a tenth of the cost for a system that works pretty well, maybe better.