If the 16 year old grandchild lives in your home or drives your vehicles then yes you are required to add him or her you your insurance as a primary or secondary driver depending on how much they drive.
Yes some 16 year old girls can get car insurance.
yes but you will be required to add the owners info too.
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.
If you want him to have insurance cover in the event of an accident you should add him to your policy. Any body that is not on your insurance policy should NOT drive your car, if they have an accident you'll have big problems.
Yes.
your liability insureance should grant him coverage, but you need to check your insurance plan to be sure.
Yes, you can add anyone you think will be using the car on a regular basis.
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.