Hm...
I thought of one [it may be N that someone pointed me to that didn't have a G version because the son's name doesn't seem to pop up on the search function - am almost certain it's Merlin]. There's twins and one is kidnapped - the girl is.
There's at least one kidnapping of one of the kids in the Firestorm series, but not until they're grown. Nan's Home series has a descendant or two kidnapped here and there. I think III is the one I'm thinking of.
