An impossible clue

I got another clue for another girls name. It is a double barrled name 1st part Mary

started like this



Very good don't be a sissy and guess I'll work on a clue, Christ IN Anyway that first one took you a while didn't it...

her name is=Mary 3 + 5 + 15 + 7 + 9 + (-1) + 7

It is an And combined they're rather ecclesiastical



......





I would be grateful if anyone can help

Regards

John