Calling home before spring break week- with good news only

I am a first year teacher that started mid year. Next week we have spring break, and I want to call a few parents who's kids are kicking butt. Any advice on opening to parents? One class I'm covering hasn't had a teacher in three months (administrative leave) another two weeks (left mid year) but some grades are in and I have a gage where they are at. so advice on not freaking parents out?