Yes and I have, if you, her own mother, can't say something, then who can? Not in a 'you need to remove your facial hair way', we had a chat about getting hair there like you do under your arms, pubic region etc as you get older, and just like under your arms, a lot of women shave it off, so did she think that might be a good idea too? If it's visible to you, then it is to other people and I didn't want my DDs to be laughed at for having a moustache. Teenage girls can be cruel enough without being given an extra reason.
But I wouldn't suggest waxing, OUCH! My DDs used my little shaving thing.