You can define, for each registration you make, if the families WITH access can see or not your share. 

For that just, in the registration, put Yes/No in "Parents can see".

To know if the parents have already seen your share just press the three little magic dots and select the option "Seen by". This way you will have access to a quick report of who has seen your share.

On the other hand, if the information you want to share requires the authorisation of the Family Members WITH access, see this article to find out how you can do it.