My DD is 6 and has just started school. She can do some really selfish things - like screaming at me she is wants different food to her usual dinner whilst I'm in her little brother's room, putting him to sleep, or waking her dad up in the morning if he is having a rare sleep in because she wants to show him something, or wants to use the iPad or something. Interrupting incessantly, screaming when not getting her way etc.
She is on the flip side generally a kind hearted, empathetic child - so we would like to explain to her that her acts are selfish and she is putting her needs ahead of others. I don't want to continually say you are whining, or you are selfish (or as my DH does call her Veruca) as that is not nice and name-calling.