how can someone view my facebook page when i set everything to "friends only"?

[vl_hj_hs]

somehow, my girlfriends sister saw something that she weren't suppose to see but im not even friends with her and somehow she screenshotted that image on her iphone and sent it to my girlfriend so both of us were wondering how the heck did her sister even saw my posts when i'm not even friend with her and my whole page is set to private from outsiders. can anyone give me any details? we spent over and hour trying out different ways to see how she can see my page but everything we've done is the same, PRIVATE. and my girlfriend doesn't use her sisters iphone also so pretty sure that my girlfriend didn't log into her fb on her sister's phone. please help???
no, there were no tags nor she even commented or liked it.
no, there were no tags nor she even commented or liked it.

[periwinkle]

May be you had tagged your gf..and thus the sister got the update on her newsfeed.

[abraXus]

your girldfriend is friends with her sister, right?

that means the ticker shares all of your girlfriends like and comments with all of her friends, including her sister

that's how it is supposed to work - facebook isnt really 100% private - never has been

thew only thing that can be done to prevent it is to have your girlfriend add her sister to her restricted list so she wont be able to see your girlfriends likes and comments (or her status updates)

[Karen]

It seems that most of the sharing and how others can see your facebook privacy settings or visibility preferences are set to friends of friends so is happened in you case.