We’ve got to hand it to Jennifer Hudson: The girl can perform in the face of tragedy better than most. First she performed a stellar National Anthem following the horrific murders of her mother, brother and nephew.

Now, she’s stepping in to pay tribute to Whitney Houston at tonight’s Grammy ceremony — but it hasn’t been easy for the ‘Dream Girls’ star. She broke down in tears several times during rehearsals. A source told Us Weekly that during this morning’s rehearsals of ‘I Will Always Love You,’ Hudson “began sobbing hysterically” and “had to restart [the song] several times before making it through.”

J-Hud wasn’t the only person in the room in tears. The source says that many production staffers were misty as well.

Hudson is rumored to be performing with Chaka Khan in the tribute. Houston used to be a backup singer for Khan before covering her hit ‘I’m Every Woman’ on ‘The Bodyguard’ soundtrack.

The tribute was planned after news of Houston’s tragic passing broke yesterday (Feb. 11). Grammy executive producer Ken Erlich said of the tribute, “It’s too fresh in everyone’s memory to do more at this time, but we would be remiss if we didn’t recognize Whitney’s remarkable contribution to music fans in general, and, in particular, her close ties with the Grammy telecast and her Grammy wins and nominations over the years.”