@Fred50
You handled it well, and technically, since your guests arrived but didn't stay they shouldn't be able to leave a review.
Not all helpdeskers are well enough informed, sometimes helps to call again if something doesn't go quite well enough with how things are handled...
A tip for the future re. the kids issue:
While we turn on the "Not suitable for children" button - nice clear, definite language!
Airbnb turns it into a soft "May not be safe or suitable for children" - completely misunderstandable which is why some parents decide to take the risk.
What you have to do is mention underneath in your written house rules that it's "Not-childproofed and not safe for children" which is nice, clear, definite language. I've read that saying an accommodation is "not suitable" for children can get you in trouble in the US, but saying it's not safe/not child-proof is stating facts.
Guests are known to not read, so before accepting a request or on answering an inquiry my reaction back always includes asking if they've read the particulars of my listing/house rules and whether they have any questions. I also mention the 'weaker' points to make sure that wishful thinking hasn\t taken over. That helps take away the thunder of commenting later about stairs or whatever.