I do not have wee ones of my own but in general regardless if it was my family member or a daycare child I only share if someone in the program has been exposed to something 'communicable that would require exclusion' so that clients know what to watch for and are reminded that should those symptoms show up keep your kid home ... this includes not just direct clients but if I have been informed one of our playgroups has something going through it.

In those cases I let all clients know the program has been exposed to X ~ what the symptoms are, if they need to be seen by a DR if they show symptoms and what the exclusion period from daycare is should their child show similar symptoms.