personally i would, i believe weaving is through boredom and can be prevented. (this is my personal view and no doubt i would get shot down from it) However i would probably ask advice from my vet aswell, as to information on whether its heridatory - have you done a google on it?
I have had a quick flick through some of the info brought up by google but most of it is rubbish. My main concern is it being heridatory as there will be very little time that they would be in the stable together for the foal to copy. Guess my best option would be to give my vet a call and see what he thinks.
I do disagree about being able to prevent a horse weaving though, with careful management I agree it can be reduced but never fully stopped (in an older horse that is, dont know about foals!!)
Well if it's any consolation Lillie - I know of several brood mares who weeve - Only one off spring has copied out of about 14. So it most definately wouldn't put me off.