Need help choosing what is right?

[Hope!]

Tell her your opinion but THAT is all you have a right to do. To get her password and delete the account is disrespectful, but also, it solves nothing! She can then get another one, that she will be sure you don't find out about. You will only make her angry.. Imagine if it were YOU who had this done to you?
You cannot fix someone's life.. all you can do is be a friend, and be respectful, kind and loving.