You might try putting up a sign on her stall to the effect of "sshhh! Mom and baby bonding, do not disturb". Hopefully, you have adults in your barn, or perhaps I should say mature people; I was boarding my AQHA mare when she was pregnant with her first foal, she went nearly a year, there was a barn know-it-all that didn't think she should lay down to rest as much as she did, so took it upon herself to go in her pen and get her up whenever she was down. I changed boarding facilities not long after the foaling, as this one didn't really have facilities for a foal, it was mostly a mixed pasture situation with a couple paddocks (I only had access to a paddock short term, as renter had her horse out for training and would have been back fairly soon). The new facility worked great, as there were only a few boarders and the owner raised quarter horses, so my mare and baby were pretty much left alone.
