I keep it to myself but do mention to the parent at pick up about how close the child is to doing it and to keep a close watch on them if they don't want to miss it. Then when they come the next day or so and say child did it I say something like I knew they were so close. Often a child takes a few steps at daycare because they see the other kids and forget not to hold on and in a sense it is like an accident of sorts. But it gives them the confidence they need that night to actually let go and do it for real. Assuming of course the parents are encouraging the child to do it too since it was brought to their attention that day at daycare. Walking is the big milestone. Others like peeing in the potty or sleeping on a mat instead of in the playpen or using a cup are milestones that often happen at daycare long before they happen at home and those I normally just keep to myself lest a parent push it at home and screw it up for me by creating a rebellious child.