Joint birthday parties

[roses]

I did actually say 'highly likely'

[Ca Plane Pour Moi]

And I disagree with you, roses. It is not highly likely that a child, especially a child who is young enough not to go to a friend's house on his or her own, will necessarily know the siblings of their friends. If that sibling is a baby (likely in this case) they may have seen the baby, but have no clue who the baby is unless the parents are friends and tell the pre-school child about who the baby is.