Your vet is the one who should be answering these questions. I agree with @chickengoggles, though. Twenty one is WAY old for a first, or even a "first in a loooooong time" foaling. I'm not advising not to do it, just to think really really hard before you risk your "beloved mare." Have you considered a nurse-mare foal? Some of those babies are only a few weeks old - as close as you can get to breeding your own without actually having to go through the whole process with Glory. Most places will only adopt out in pairs, but will allow the second foal to be a "foster" until it's weaned. Most also require the presence of an older, more experienced horse (like Glory) to teach the babies how to be a horse, instead of the four-legged human they seem to think they are. Look into places like Last Chance Corral and such. You may just find your next equine soul-mate ... wobbly knees and all!Twenty-one is awfully aged for a maiden. What does your vet think?