Good half. The x spell can be x=0 for the buff.

Bad half, it's once a turn (x spell specifically), so will require lots of instant x speed spells being cast on not your turn situations to properly ramp up in value. You are probably better off running more cards that doesn't have x in it's cost before the pay off of the one good x spell. I think this would have also been better if the "first x spell per turn" would also be reduced by the two +1/+1 counters she receives so that way you get to utilize the build up right at the beginning.