I don't think this situation should be addressed in bylaws. Bylaws need to be basic guildelines and require action by the guild as a whole when changed. Perhaps you have a list of expectations, such as each member is to contribute to charity quilts, etc. This might be the place to address disruptions. Our guild has more trouble with disruptive adults who visit during the business meeting! I like the wording someone else suggested that addresses the children present and the dangers involved with quilting equipment. It explains the reason for limiting attendance. There needs to be a tactful way to address the situation, no matter the age of the disruptee.