Best Friends

Had a situation the other day that made my toes curl...
I have a lot of things going on in my life at the moment and haven't share anything with anyone, especially with close friends, for many reasons... but the other day my best friend came over... and we're chatting... casually... the phone rings... I answer... it's the sister in law... I chat for a few minutes... and hang up. I mentioned that the sister in law is a little upset with me. 'Why?' Asked Best Friend... 'Because she learned about some problems I've been having from someone else. She feels that we're friends, which we are, and I should have told her first. But I don't feel that you guys need to hear my problems.' Reply from Best Friend, 'We don't.'
I haven't told her anything about my life and it's issues for many many months now... Am I missing something???????
BTW: she still and never will hear from my mouth any problem I will ever have...