Did I do the right thing or the wrong??

Okay, so last night, I was getting my partners phone ready for him to use.. I saw that the notes which were on the phone were still there after a factory reset.. So skim read through to see if they were important to his sister or not.. But one of which I skim read was depressing and so sad, and went to her older sister about it, so she could talk to her.. If I didn't open my mouth my partners sister who he bought the phone off wouldn't have known, but I was concerned about her.. She was extremely upset and angry about it, and seems that it was something she didn't want anyone to see.. She is absolutely angry.. And cannot see my side.. All I was trying to do was get my partners phone ready for him and make Sure there wasn't anything important on there..