Some people boil wine before imbibing it, or so legend says.
Boiling wine removes the alcohol from the product. You must have the temperature of the boiling wine above 176°F (or 78°C), which is the boiling point of ethanol (alcohol). Achieving a temperature between 176°F and 212°F (boiling point of water) is quite intensive, but possible. A tall, thin pot (the taller, the better) is the best way to remove alcohol. I'm told by a friend of mine, he does this and says it works the opposite of a still.
I doubt that your children will like the new creation, because the taste of the tannins in the wine becomes rather pronounced.
It might be best to purchase the kiddies some sparkling grape juice, or make your own by adding seltzer water to regular grape juice.