Are you experienced in taking care of children 2-4 years in a rich\influential homes, this is your opportunity because the pay is high and you will never regret it if you are looking forward to a great career too.
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.