I can't imagine Maka's mom as the joker type either . . .at least not like Death Scythe or Stein. Very likely she has soem similarities with Maka in terms of attitude (since I think the reason of the divorce is Death Scythe's cheating ^^
and she may act for humor at times since . . . we're talking about Soul Eater after all xD Which character doesn't have even a little crack? haha xD