My dd will be 10 in a few Weeks. We are taking some of her friends out then out for tea then sleepover. The day will be very expensive but I wanted her to have a good day. Thing is she is being very badly behaved lately. She shows a complete lack of respect for me and Dh. Screams at us and doesn't do as she is told. She has become lazy and has the attitude of a teenager. I have threatened to cancel party as other punishments haven't worked. Would this be too mean?