What's the most polite way to tell your relatives not to bring their kids to your wedding?

I’m getting married in June and we’re not having a big wedding but I have a pretty large family and they all have kids under 10 years old. We’re having a small dinner party at a friends house but she has a pool in her back yard, so aside from not wanting a bunch of little kids running around, I don’t want to be worrying about a child falling into the pool on my wedding day. I mentioned this to my mom and she thinks that some of our relatives will be offended if I tell them not to bring children on the invitation.

Frankly, I don’t care if they get offended or not but I guess my mom does and I don’t want to upset her so I don’t know how to go about this small dilemma. Any ideas?