We have two guilds locally. One is quite large and even amoung the members has a reputation for having several unkind people. Because of their size, they are able to do a quilt show, bring in speakers, etc.
The one I belong to is fairly small, w/ maybe 60 members. Monthly business meeting (brief), helps (if you have a problem or question regarding a pattern, quilt, etc., you can ask for advice), show and tell followed by a short presentation by member for a technique, tool, or small item. Strip exchange for those who want to participate. We do a charity quilt & sell tickets to raise money for a local charity, voted on by members. Bus shop hop once per year for anyone who wants to sign up. Each month there is an opportunity to meet for help with bastings, too. And every couple of months we have a "sew in" where anyone can bring whatever they'd like to work on for the day, a snack to share. Occasionally a Saturday class, usually taught by members (bag making, table runners, etc.).
Our dues are $20/year, enough to cover a donation to the church we use, occasional donations to local causes, and a little left in the treasury.
You didn't mention the age of your children. I agree with a previous poster that many of the quilters look at the guild meeting as their night out, and may not appreciate having children there. My children are older now, but I know when they were younger there is no way they'd be able to sit quietly and not disrupt a meeting that lasted an hour or two. Depending on who else you know that sews, a moms group might be a great idea. Or 4-H (where I learned to sew a hundred years ago!) - they are always in need of new groups or helpers for existing groups.