what if i am doing this wrong??/

Ok, broody hen, gave her 3 eggs to sit on, today is day #8. Broody Momma (as i am calling her) will not get off the nest unless i take her off and put her on the grass. She stays out about 15 - 20 minutes. Long enough to dust bath, scratch around and back in she goes. No food or water time. I have put a styrofoam cup of food and water in with her. She has lost a lot of weight and seems week in the legs when i take her out. I got her eating McDonalds cheeseburgers the last two days. can you say SPOILED!!!!!! She has chosen a nest box in with my other 7 girls. I did not move her out of the coop (8X10 shed tajmahal). I can get her to eat started food with water out of my hand, but she doesnt seem to eat any on her own.

I know they are supposed to get out of the nest box once briefly to eat, drink, and poo. Is she ok? This is her and my first sitting! I am a nervous expecting momma here... Can i keep her in the coop with the babies when they hatch? or do i need to move her and the eggs out immediatly.
Nervous Nellie here.... think i am worse than she is.

 

how long is to long for her to be off her eggs?