It’s really quite clear although we haven't seen her yet. And actually, it’s rather logical. Who else would be taking care of good old Santa, way up there at the North Pole, all year long? And who would be helping Santa pack all those wonderful Christmas presents? 

This kind lady is quite unknown in Europe, but in America the Santa Family wouldn’t be complete without her and all the little childlike elves and cherubic angels. Indeed, there are even some researchers in Europe who claim that Mrs. Claus is the one who “rules the roost” in the New World. That doesn’t bother our good old German Santa Claus  he grins and laughs and has his own thoughts about the matter!