Blueyedgirl
It is very obvious from the thread that this is not a vendetta and that in the situation described by the OP you were quite rude.
It is also obvious that some of the jokes on this thread were equally rude.
But people are allowed to and should "warn" others as you advertised for some work as a nanny on a public forum. As a nanny you just cannot behave like that because that job is solely based on trust and gut feeling: no matter all the references, checks, etc at the end of day you are on your own with their kids in their house and you have a key.
Of course you should stand up for yourself (and the jokes made about you were not nice), but you should start by apologising to the OP and explain yourself clearly (sorry but it is difficult to read you).
So far YOU have let yourself down.
S.