I've learned when people use the word obviously around here, it almost never fits correctly, and is usually based solely off of their subjective opinion based off of predisposed, slightly educated conjecture.
She said that the water hadn't just changed to hot. The knob had actually been turned all the way to the hottest position, but not by her sister. And I'm sorry, but your second rationalization isn't even really trying.
But at least you didn't go for the seeking publicity route. Seriously, what actors/singers would use 'a house I used to stay at was haunted' in one conversation with a magazine to hopefully further their career? She is #1 on Maxim's Hottest star list. These people don't concoct campfire ghost stories to further their publicity, do they? Nah, they talk to magazines about whatever, and people ooh and aah at it all the same.