I think there is a way to hide your profile pic from the general public (people who might search your name) so I imagine the album can be private, too. I've always assumed since my pictures are set to friends only (along with everything else that can be friends only) my profile pic album is private, too.
If are friends with someone, but not with their SO, you could ask them to search you and see what they can see. I've done that before.
SAHM to my 3 growing kids. They keep me so busy I don't have nearly as much time to hang out on the BBB!