Tell her she has two choices:
1) Delete everything (account, pictures, etc.)
2) Get sued for "intrusion of solitude", "online harassment" and "reputational harm".
Brother some people think is funny or doing you a "favor". Many times you are to blame for them doing that. Because in your friendship you never draw some lines for them to not crossover. I do not know, but it seems like this sister is at fault for letting it get so far. For example, if you (in general) always complain to not have a spouse, that is also a indication for your friend to "help" you with it. I do not know if that is the case with this sister, as there some "friends" that they themselves feel the stress, although you are calm and feel no stress..they take things in their own hands and suddenly do things that you never approved of or notified them by whatever means to do something for them.
For example, i just went to a new apartment and i did everything myself. Painting, doing the floor only a few minor things i asked for help because it needed multiple people to achieve it. I took my time doing all those things myself. However, ever week he would ask me..have you already finished everything? I said ..no. I kept it calm. Slowly finishing things and he was being annoyed because of me taking MY TIME to do MY STUFF.

?? I suspect that he himself is stressed all the time and he has this mentality to do things and want me to behave the same way as he does. When i finally was finished but did not clean everything yet..i said, when everything is also clean, one of the rules in this house is, everybody will have to take their shoes off when visiting. He said, that is being disrespectful. I said how come, those are my rules in my house. He said i will stay outside then

?. So i guess there are people who really want it their way and think without them the world cannot function =_=!.