I would question the claim that women are better drivers. Better is a statement which makes a question subjective. Better drivers than what or who? And Better because they do what?
I am guessing though that you mean better and have less accidents than men?
I remember several years ago there was an insurance study which found little disparity between numbers of accidents. Women in the study had as many accidents as men within a small margin of error.
The main difference was the type of accident, women tended to have low speed accidents, hitting cars in car parks or hitting small objects causing minor damage and so less cost to repair.
Men however tended to have higher velocity crashes in which one or more vehicles were total "write-offs" therefore a worse risk for insurance companies.