I have a BIL who is a dentist, but he also knows how to do plumbing, electrical, carpentry, fix cars, and about everything else. These are skills that no one else in my family shares. And he and my sister live near my parents and other brother, the doctor. They have been married for 20 years. For the first 15 years, BIL was Mr. Fixit for my parents in both of their houses, and my other brother. They bought ceiling fans, microwave ovens, window air conditioners, etc., and called BIL to come install them. For 15 years. When my brother, the doctor's, heat went out in the middle of winter, did he call a heating contractor? No. He called my BIL. Heating contractor would cost $90. Finally BIL had enough. He just stopped being able to help them. When they call he says, "I don't know, I don't think I could fix it. You better call someone." He has his own house and family to take care of. It's time for your MIL and FIL to start calling professionals to help them too.