At the age of 8, children can sit in the back seat without a booster seat. They do need to have a seat belt; however, and not be in the front. They need to be securely fastened as well.
A six year old can be placed in the front seat but they must use a booster seat if they are under 135cm tall. Under no circumstances should a rear facing booster seat be used in the front seat.
Most seven year old girls should still be in a booster seat. So yes, she can, especially if the parent does not feel comfortable with letting her out of it yet.
Yes
It's reconended that you use a booster seat up until the age of 5 ears old, or until you're tall enough, but technocally, it is for your parents to decide.
Whether or not your 12-year-old needs a booster seat in the car depends upon the laws of your state. Each state seems to have different rules about age/weight/height requirements.
you have to be 12
You have to be 10 years old
I tried to get my pa to ride in the booster seat because he is gettin' kinda short in his old age but he just refuses. You think your 5-year old is stubborn? You ain't never dealt with pa.
5 years old
Yes, but if there is a air bag it has to be turned off and the child must be in a booster seat.
12 and under
Eight