Does anyone know more about Facebook settings

[Troels]

I've joined a private group (you request to join, answer questions to get in) it's on facebook for an illness I have, if I post on the group, can all my friends and family see what I say?
I'd rather not tell the world what I'm going through until I get a handle on it myself

No if it's a private group only other members of the group can see the posts.

Thanks for that, I won't feel so self concious posting.