I received my confirmations and was looking over all the final details last night. On our master confirmation it shows DME for 4, but I only received 2 adult vouchers, do the kids need one also?
How old are the kids? Typically children under 3 do not need travel vouchers for DME. Depending on the CM's they might issue you one anyway.
If the children are older than 3 I would contact DME but, if your reservations indicate 4 in your party you could probably just get two replacement vouchers from the DME welcome center when you arrive. They can print them up right there while you wait