Kids are not welcome in most facilities, but again, that's because of cost. They try to say it's "your time" but really it's because it's expensive to have childcare. Offering childcare raises their insurance, and they'd have to hire an additional employee to be in charge of the kids. And they might even need more space since many Curves are located in single, small rooms. Curves is a very inexpensive biz to run and in part it's because they cut the "frills" like childcare, showers, locker rooms, etc. It's basically the machines and that's it.
Having said that I am envious of Megan and her Curves

I would get there more often if they had childcare. Do you mean the Curves you go to has childcare or just children are allowed? I could easily bring my 5 y/o and let her play or color, but if there wasn't actually *childcare* I still couldn't go with my toddler. He needs someone to watch him or he'll climb on the machines, mess with their computer, write on their walls

Actually, while technically kids aren't allowed, I did once see older kids (like my dd's age) at my Curves, sitting and coloring while mom worked out.