Am I liable?

I currently live with my parents who are 87 and 88 respectively to take care of them. Both of my parents have the beginning stage of dementia. My father is very hard of hearing and has a retina tear in his left eye which left him with no peripheral vision in that eye. I provide transportation for them to all their doctors appointments as well as any other places they wish to go to. I accompanied them during their doctor visits because they are both hard of hearing. In addition I also take care of things around the house. According to Fairfax County's law am I consider a caregiver?

My father has been advised by his primary care physician not to drive and when asked by the physician if he is driving he told his physician he is no longer driving. However, there will be day when he will insist on driving. If he gets behind the wheel and hurt someone, am I liable for allowing him to get behind the wheel when I have knowledge of his disabilities and his physician recommendation?

Thank you in advance for any advice you can provide in this matter.

Sincerely, Betty