How much should i charge to be a companion to a handicapped guy (and would it be worth my precious time)?

one of my neighbors has a handicapped son, who is about 35. he is in a wheelchair and has a catheter. he is entirely independent as far as his medical conditions, in other words, he can take care of himself. i am a single mom in my early 40’s. i work full time, and several nights a week my daughter stays at my mom’s, in order to free me up to shop, clean, etc.

the neighbor, who is in her 60’s, told me she would like to occasionally be able to go visit her family a few hours ride from here. she asked would i be willing to stay at her house from about 8 at night to about 8 in the morning. There’s a spare room i could sleep in. the son just needs to have dinner ordered, needs to have someone get him stuff from refrigerator, then i could go to sleep, get up, make him toast in the morning, and leave (an aide comes in the late morning). nothing medical or physical touching of the guy involved.

my free time is rare and precious. it does not seem like there would be much effort involved, it’s more of a time issue. if i were to help out this woman by staying at her house occasionally to be with her son, how much would be a fair amount to charge?