One of my kids was like that... Nice, courteous and well-mannered... Until getting what he wanted.
I attributed that to the circle of entitled athlete teammates of his...
That shit ended. I stopped giving him shit going 7 years on. He'll pay for that as long as I remember how much of a bastard he was for that 6 months.
With Heather, I'm sure she still thinks she's all that. It's always everyone else's fault a la Falkie, etc...