Firstly let me say many congratulations on your new healthy colt
Secondly may I also say how lucky you are to have a caring, protective mare! She is following her instincts at the moment and IMO anything you do to try to 'break' those instincts is only going to stress and frustrate her. Here we are strong believers in the fact that babies belong to their Mommas, they are not ours to fuss and fiddle with. We are always there for the birth to offer assistance if necessary, to help break the bag and to dip the cord. After that there is a warm feed for Momma and pain relief, again if necessary, then we are 'out of there'! O focurse we are watching for the afterbirth to fall away, to collect it and inspect it, but other than that and keeping an eye on the progress of the foal, we do not interfere in any way. The mare is left to bond with her baby in peace and quiet - we have also found that babies learn to drink a lot more quickly if left alone, instinct will drive it to keep looking for Mommas 'sweet nectar' even if it takes several hours! We used to have a lot more trouble in the past when we got over anxious about baby drinking, and used to try and assist. (All this is supposing that there is nothing wrong with either mare or foal)
For the next day or so Momma and baby go out into their own private space, which is when we muck out the stable and bed up again. After the first day some of our mare are happy for us to clean up their droppings/stables when they are in there - again we ignore the foals - but some are not and we respect that and simply continue doing the stable when they are out of the way. On day two or three they are able to join the other mares and foals during the daytime (all mares and babies are in at nights for at least two to three weeks depending upon the weather) - I would never allow them to join a mixed batch of horses at this stage.
Rightly or wrongly, doing it this way, we seem to end up with relaxed mares who are happy to bring their babies over to see us when we visit their field in the day and babies who have no fear of us as we have never forced ourselves on them in those first few days. In fact the babies just wont leave us alone and by day four or five we are bombarded with little bodies if we sit down on the grass in their field LOL!! Visitors always ask what we do to make our foals so friendly, and we can truthfully say' absolutely nothing'!
My advice to you would be to leave your little mare and foal well alone to give her the confidence that you will not interfere with her foal. As it is apparent that she is a good Momma, can you get your other horses stabled for at least half the day, so she can have space to herself - your foal may well get injured otherwise and Momma's milk supply could be affected by the stress of proteting her baby.
A couple of pics to prove my point (although I will state again that the above is the way we choose to 'handle' things and just my personal opinion).
Three day old foals...
And four and five day old foals...
Wishing you good luck!
Anna