Back in those days I would guess that most family’s only had one car, with the husband using it in the week for work. As the husband was the main driver it would seem perfectly natural for him to drive the family car at weekends also. This meant that the wife was an occasional driver, so lacked both confidence and experience. My wife passed her test at age 17 but didn’t have her own car until many years later. By contrast, my daughter passed her test at age 17 and drove her own car immediately. My daughter will drive absolutely anywhere, any distance without thinking about it, whereas my wife still prefers only local trips. When it comes to speed, my daughter would give me a run for my money, but then it was me that taught her to drive and got her through her test so I shouldn’t expect any different.