My dad and I do the same thing. I worked contract with him for 20 years. Now I work for the same small company he retired from. We do structural steel design and shop drawings. I do a good bit more of stuff he never waned to mess with like going to the field, estimating, and programming some of the CNC equipment. My dad had the dream job in my industry, those days are over. He worked at home, got a company car/truck, and mostly went in on Fridays to get his paycheck and eat lunch. He also was allowed to work on the side nearly full time if they didn't have anything to do. He wasn't paid as much as a lot of people but he made just as much if not more on the side most years and got insurance and guaranteed work at a minimum. He still does some work in retirement when we need help or someone has some odd stuff nobody else can do.
My mom worked off and on keepng books and running offices. She did some of it to get away from dad who worked from an office at home.