Hi J.,
So sorry that you sent the email off to your current babysitter in error. Without knowing the amount of children and their ages that are being cared for but working with what information you have provided, I would be looking around using every resource to search for a new babysitter.
I would not offer any apology for sending the email. The dollar amount for a trial day??? Was this anything both of you even talked about when you hired her??? Red flags are popping up with this person charging for snacks and beverages.Who or what is determining the dollar amount for these goodies?
Have you seen any grocery receipts for what she has provided your children?
I would not argue with this person but be firm in what her services are worth to you.
Good luck in your decision making,
Mary