Yes some 16 year old girls can get car insurance.
A 17 year old can get a temporary car insurance, but it will cost quite a fortune.
There is no set price for car insurance for an 18 year old. The amount will be determined by the car insurance company, and the person's driving record.
There are too many variables to be able to give you an estimate. It depends on the car, your record, and how much insurance. For an accurate price contact an insurance company.
I heard you do not have to add your 16 year old to your car insurance policy since he/she will only be driving your insured car. Is this true?
Yes.
Depends on car.
Yes.
One can obtain car insurance for a 17 year old by looking on Progressive, a company that specializes in pairing consumers with car insurance providers. Progressive has an option for minors and young adults.
In California you have to be at least 25 years old to rent a car. Insurance companies will not give an 18 year old rental car insurance. If you do find a rental car company that will allow you to rent a car from them, the insurance you have on your own vehicle will cover the rental car as well.
Contact an Insurance Agent for a rate quote. There is no such thing as an average cost of car insurance for a 17 year old or any other age male.
As long as she owns the car, has a license, and can afford the insurance she can buy it.