Something quite similar to this happened to me. My friend was at my house and she wanted to go on FH, and I was like "sure." It turns out that she was trolling e.t.c and got banned for a year! Now me or my siblings and friends can't use our FH accounts for a WHOLE YEAR!!!

Ughh it's annoying isn't it! It's something to do with your IP address I think.
But, like everyone else has said, how do we know it was your sister and not you? It's frustrating, I know. But it's only a week. You should be able to live, shouldn't you?
Also, there isn't really much you can do apart from wait. I've tried everything, from PM-ing mods, posting here on the forum, deleting FH and re-installing it again, and asking around elsewhere on the web. I've had no luck. Ah well, I guess I'll have no FH for a year! *cries*
Just make sure your dang sister doesn't do that again!!!
