I actually would be fine with a MIL cleaning my house... LOL My own Mom used to do that when she visited me. I was working 60 hour weeks and never had the time to clean (I eventually hired someone to do it). BUT... it's HOW they offer. My Mom made it clear she just wanted to help, and if my MIL had the same attitude, no problem. If there was an implied criticism, that would be different. Or, if she offered and you said "no thanks" and she did it anyway - that is disrespectful.