I'll give away a beach suit for free or for an apple, I don't remember the size. It was a little loose at 1 year old, and it was already tight at 3. I'm inclined to think it was 2T.
Never pay down a deposit in a bank account until you have met the seller, seen signed a purchase agreement.
No serious private advertisers ask for a down payment before you meet.
Receiving an email with an in-scanned ID does not mean that you have identified the sender. You do this on the spot, when you sign a purchase agreement.