If you want to be welcoming and inclusive and still deal well with the kids underfoot problem, I suggest that you have a very clear statement -- "Because our meeting space is limited and we work with potentially dangerous tools, children may not be in the meeting space. Any child brought to the guild meetings will be supervised in a close-by playroom by a paid, certified childcare professional. Please sign up a week in advance for childcare. Day-of availability is not guaranteed and will be an increased cost. The cost per child will be X."
Or you could encourage parents of young kids to form childcare co-ops where they take turns watching kids.
Or if your guild wanted to do it, they could provide free childcare, with guild members taking turns and connecting with a new generation.
I think there are all kinds of ways to reach your goal -- appropriate environment for guild meetings-- without seeming unwelcoming or ageist.