I work at a daycare and I am there 9 hrs a day. At 12:30 we are allowed to eat lunch but we are NOT allowed to leave and we do NOT get paid for it. Is this legal?

That, in and of itself, does not mean you must be paid for the time. Why do they say they are prohibiting you from leaving?

I'm not sure why we are not allowed to leave for lunch. It has been this way since I started working there. I understand the fact that they do not have to pay us for a lunch break, that is not a big deal. But can they make us stay there for "lunch" if they are NOT paying us for it? I thought it might have something to do with staff-ratio when it comes to working in a facility with kids, but there are other daycares that allow their employees to leave for an un-paid lunchbreak!

Are you subject to being called back to work in the middle of your lunch period? Regarding why, "why" don't you just ask them? If they have some reason, then we can determine whether such a reason is such that would require compensation for the time.