Hacker, virus or playing games?

The Facebook account of one of my friends seems to be doing strange things:

- when she likes statuses/photos etc. her likes sometimes disappear, as if she liked them and then unliked them again
- some of her pokes have disappeared, as if she poked someone and then deleted the poke in the activity log
- friends get unfriended for no apparent reason, when she notices, she adds them back.
- once her account seemed to have been deactivated for 10 min while we were chatting. I couldn't send her a message nor see her profile pic for 10 min, and in the meantime she texted me to say that something was wrong with the messenger/Facebook app)

She claims she isn't responsible for all of this. Does anyone recognize these problems or know what could be the reason for them? A virus? A hacker? Or is she playing games with me?