They didn’t want to fire her, but she did want to quit. She wasn’t happy with the direction they were taking her character. I wouldn’t be surprised if she also had issues with the same guy McFadden did. Jadzia was killed off because Berman wouldn’t let Farrell switch to being a recurring rather than a regular, which may be what you’re thinking of.
That was entirely dependent on Stewart’s contract negotiations, though, rather than anyone wanting to kill off Picard.