I think she is one of the few Broadway actresses today who has perfect comedic timing. No one can say, "I love your top! It is so fatigue sheik! So, how psyched are you guys! Snaps! First Day of Harvard Law" better than her!
I have read interviews with the creators where they have said that the end of the show will basically be "and this is the mom, the end" in the last episode. So, it's highly unlikely that Bundy is the mom, especially since she's blonde and they made that fake-flashback with Stella (also a blonde) where the kids are blonde, and Ted's kids both have brown hair.
"You don't just stop posting horse s*** on the web!"-The [Title of Show] Show