Apparently her first day went alright.
Jen Pawol makes MLB history as first female umpire to work a regular-season game
That is, nothing happened except umpiring! Which should be the case; we should not ever need to be talking about umpires, if you think about it.
Today will be another test with her behind the plate. She has to be experiencing some butterflies, I imagine.
Of course, her ultimate challenge will be when Aaron Boone gets into her face over a call that he doesn't like. All's fair, of course, and she has to be able to take that crap.
EDIT: ESPN has a better article:
https://www.espn.com/mlb/story/_/id/...ar-season-game