I wrote down the passcode so that I could use it to access her private information
Why would you want to get into her social media.
Well she gave it to me, and trusted me to never do anything bad with it.
I think that she trusted you! You should not access anything personal and especially you should not use the info against her!
I'm okay with breaking all of those promises as long as I can stop her from posting about her breakfast.
She trusted you thinking you would only help her out and not sabotage her media accounts. Please reconsider because if other people find out they might never trust you.