He has to be changed, put in a wheel chair. The Mother gets around pretty good. Has problems sometimes. I cook, clean, take care of the yard, go grocery shopping, take them to the doctor. I'm here 7 days a week. I have a room, share the bathroom. What is charged for this work?
Keep in mind that your are caring for two people. If this were only housekeeping, the number of people hardly matters -- mowing the lawn for one person in a house isn't different than mowing for a family of five. But for actual caregiving tasks, two is twice as much work as one. It sounds like the son requires caregiving. What about the mother?
You need to also determine how much time off you get, and how the elders are cared for when you are off? If you go to an out-of-town wedding some weekend, who arranges for their care? If you go to your bowling league every Monday afternoon, how is their care handled? No one can provide 24/7/365 care and retain their sanity, so this must be considered right from the start. Is Mother well enough for them to be left alone a few hours? A few days?
Are you related to these people? How did you come to start caring for them? Do you have a valid contract in place? Do they withhold employment taxes?
I certainly hope that you can work out a fair financial arrangement that suits all of you. This kind of a care situation can be ideal, and can keep impaired elders out of care facilities for extended periods. But it has to be fair and satisfactory to all concerned.
Let us know how you work this out. It is a frequent question here, and we learn from each other!