has been cast in the much-anticipated 100th episode of How I Met Your Mother
, according to EW
It's not clear whether the 28-year-old actress will play the mother
(as in the show's title) or the mom's sister, best friend or some other relation.
FYI: The show revolves around Ted (Josh Radnor
) recounting to his son and daughter the events that led to his meeting their mother. How I Met Your