It depends on if she has a clean driving record. Are you adding her car to your insurance, or just adding her to your insurance for your car? If your adding her car then the year and type of car determines how much it will go up. Say it's a 2008 mustang or something, then it would sky rocket. Sports car's and some newer cars are more money to insure then older cars that aren't sporty. Also she's 24, usually at 25 your insurance price is lower. Call and ask progressive about it. They can give you a quote and tell you how much it will be.
