Hey JahJah,
Don't be getting all exercised now... I have nothing against you (or your Mom). I have a Mom myself and she worries about me regardless of what I do (I haven't gotten the nerve up to tell her I cave dive yet).
I have no problem with you and your friend diving with us... Hell, I'll even be your dive buddy if you want. I am more concerned about later on, back at the campground. A lot of us are going to be drinking, being silly and otherwise acting up in ways that may be inappropriate for a 17 year old to be around.
Just speaking for myself, I'm going to have my girlfriend there with me and knowing myself as I do, I'm liable to get all drunk, get back in my camper and make enough noise to entertain the entire campground. Knowing that there is a 17 year old (and his Mom) sitting outside could throw a monkey wrench in the whole thing...
Maybe you, your friend(s) and your Mom could set up camp a little ways away from the main camp and if things get a little too risque, you could retire to your own little campground. I've been on a lot of campouts where people have done that and it has worked out perfectly for everyone involved. Just my $.02
Rick