Right now we are on the opposite side of the conundrum: we have chosen the name Beatrix for our new baby, but we don't announce our children's names before they are born. I am wondering what to say to semi-close friends whom we have known for 20 years but only see half a dozen times a year whose daughter is named Beatrice [Italian]. Though our choice of the name is not related to her at all it does seem appropriate to acknowledge the close link between the names.
Our Beatrix is due in October. Let you're friend know we're using it, too
We don't share names either, but in this case, you might want to float it by in a group possibilities. For example, find a time to casually bring up names and rattle off a few that you're "considering"... put Beatrix in there. If you feel like you owe them a heads up or explanation, there it is.
OP. similar advice, although I think it's totally fine, especially if the kids are completely different ages.