Mrs. Claus was always presumed to be: as far back as the 1850s St. Nicholas was like the US President and bachelorhood was not fitting nor proper. Reverse engineering supplied her with duties (feed the elves, compile the list, brush down the reindeer) and a personality–which varied with the decades. Doting, persnickety, peevish, demanding, sexy suited the contemporary matriarch of the time.
Did she have a name?! By the mid-XX Century funny storytellers were willing to brand her with some moniker. I mean, come on, agreeing to a name would show the dame respect, like with Kris. (Saints Row IV from Volition mentions Mary–yikes! is JC their kid?!) (I guess Peanuts cartoons also use Mary, but then Samantha.) (Movies make use of the names Anya, Margaret, and Carol–ha! good one.)
Rankin and Bass ‘animagic’ TV specials from the ’60s call her Jessica. We’ve tried the “Wedding Day” song (S.D. Kluger) from their 1970 Santa Claus is Comin’ to Town. But check out her I’m-falling-in-love moment of pop song psychedelia “My World is Beginning Today,” sung by Robie Lester.