What should a part-time person who does errands and driving to doctor's appointments be paid?

My mother has recently been put on oxygen full time and is quite independent at age 95, but will need someone to take her on errands and doctor's appointments now. Along with instruction with certain things in her home. Yes, she lives alone & won't budge :-) We are all 3 hours away and visit often, but a wonderful neighbor is helping her out when we are unavailable...as we can't go home as often as she would like. Question is: How much should she be paying her for this help? I believe she is currently giving her $25 per "excursion" - and they do use my mother's car each time. Help? Also, I believe we should do something for this saint of a person for being so good to Mumsy when we can't be there. Ideas? Perhaps a Christmas bonus or gift certificate? Clueless here.