My Friend's Facebook problem?

My Friend Annalise and I, does roleplaying on Facebook. And nobody in our life knows about this except us. We have alot of Roleplaying accounts we made. And made alot of roleplaying friends. My friend, Annalise called me right now and had freak out. She said she was almost caught by her sister. Let me give you full detail what my best friend said. She said she was roleplaying on one of her roleplaying account. Her sister walks into her bedroom while she was on her laptop roleplaying. Her sister thought she was on her REAL LIFE Facebook account. When her sister came much closer to her laptop to see what she was up too on Facebook, My friend quickly turned the laptop away from her sister and quickly logged off. Her sister wanted to know why she did that. Her sister got mad, and told my friend to get back on so she can see what she was doing. My friend logged on her RL account and told her she was doing nothing. Her sister told her that she's been logging off when some of her family members comes into her bedroom. My friend said to me that the reason why she does that because she doesn't want to get in trouble if one of her family members find out of her roleplaying accounts. Now her sister thinks my friend is hiding something from her and her sister told her mother about this. Her mother agreeds with her sister. That's she been logging off when they come into her bedroom. They warned her that they can get on her laptop and see what's she been doing. My friend is scared that she might get in trouble by her family members if they do find out about her Roleplaying accounts. My friend gets ON her roleplaying accounts everyday and night to reply what her roleplayer left for her. Because the roleplayer told her to come ON everynight. But now she's too scared to come ON because her sister might get her again. What should my Friend do?