my daughter started full time school a few weeks ago and recently her attitude stinks,she has an answer for everything and when someone askes he to do something she just replie NO ! she is rude to not only me and my partner but my parents too,we have a chart and a naughty step but nothing seems to be working, i understand that she is going to be tierd with the new school but even at the weekend she is like after a long nights sleep,whats anoying is i know when she is with her dad on a sunday she deosnt act like this and i feel im spending all my time shouting at her instaed of doing fun things with her...............please some help i really dont know what to do

A lot has changed for your daughter. Starting school is a BIG thing and is stressful for children. Her behaviour is undoubtedly a reaction to that.
However, you can't allow the behaviour to continue, even though you know why she's behaving that way. Just try to remain calm and be consistent. Try not to shout too much. When she is being good, lavish her with praise. When she isn't, explain it's not ok to be rude and then ignore her if she continues. So "When you speak like that, it's rude. I need you to do this now etc." The chart and naughty step seem a good idea. Keep using them... They'll work shortly!!!
I'm sure this phase won't last very long....just be firm and "normal service" will resume very shortly!!!

I do not believe charts and praise are good because these are ways of manipulating and controlling the child.

Children behave well and thrive when they are happy! Find out what is difficult for her with the new school. She needs your understanding and help.
When you know what it is that is hurting inside her, you will know how to remove the problem.

School can be a really harsh transition for a seven year old. Have you considered home-schooling?