Wow, this thread and related ones are turning into right car crashes. Although you (the op) stated a couple of times that you have "decided not to be spiteful", it doesn't sound very convincing. It does seem like you were more than a little disappointed that you were unable to give a bad reference for the au pair in question, but that might be a bit harsh?
Even though it seems like you weren't entirely happy with her performance working for your family, you were happy to keep her on until the end of her contract. Furthermore, I don't believe you are qualified to judge whether or not she would be "hopeless" looking after newborns when she was not looking after any young babies in your own home (if I understand correctly) and you yourself did acknowledge that she is good with toddlers and older children?
Your claim of altruistic intentions doesn't ring true to me and I haven't the foggiest why you would waste so much time and energy on such an issue (and getting lawyers involved ).
Apart from the troublesome fact that you heard these claims from a third party, I'm having difficulty understanding what she would be doing with all the stolen "merchandise". I mean is she selling them on ebay or from the back of some clandestine warehouse!!! Fair enough about the toiletries, but washing powder and food?? Perhaps she was admitting that she was taking these things behind your back because she felt you were not providing for her needs (which I am not saying is the case), which I guess could still technically be called stealing??
I'm not saying she wasn't a bad apple - there's plenty of them on both sides but as others have said, in that case why not cut your losses. At the end of the day she's a young 22 year old girl with plenty to learn. Surely it would make your life (and the rest of your family's) so much easier to just move on, find a replacement asap and not give it a second thought.
Why are you choosing to put yourself through this stress and hassle if it is not because of sour grapes, or else, perhaps your judgment has been a bit skewed because of how hurt you feel over how you've been treated. We're all guilty of that sometimes, but in my experience, harboring resentment and ill feeling is toxic and usually does you far more damage to you than the person that has "wronged" you.
My advice would be to LET IT GO, LET IT GO, LET IT GO. Count your blessings, appreciate your beautiful family and put it all down to experience.
and here's a few tips of how to do same:
http://tinybuddha.com/blog/40-ways-t...eel-less-pain/