@Rita504 Have they checked out, or were you just checking on them? If they have not checked out, I would probably just politely say that if they have any more suggestions for things that need to be fixed, to let you know about it. I would probably word it something like, "Thanks, but you didn't have to do that! I'd be happy to take care of any issues for you."
If they have checked out, I would let it go. It really sounds like their hearts were in the right place. We should all be so lucky to have guests fixing stuff rather than breaking stuff!