How can I tell who I shared my photostream with?

I've created photostream albums and have shared with family members but now can't remember which family members I've shared them with. I've also created my own photostream album so I have access to that particular album on all devices and now wonder if all family members can see that too? Does anyone know how you can tell who you have shared your photostreams with? And if all shared photostream albums are shared amongst all?