Ugh - I'm SO conflicted!!
She responded to my email and said that she will need me a couple of times in the summer and has to report back to work on August 11.
I did tell her that I want to re-negotiate her contract and have a deposit to hold her spot. We will certainly be talking about the fact that her contract says pick up at 4pm and she never does. I will be informing her that I will start to enforce the fee as stated in the contract.
I don't want to be a witch, but sheesh. I've really enjoyed her child - he is a year old and has been with me for the last 10mo. I love that little guy like my own, but his mother makes me want to scream.

Unfortunately, she's not as bad as it gets and I never know WHAT I will get if I cut her loose. Trust me - it could be much worse.
Thanks for listening and for all the replies. DH doesn't get it.