She needs to learn defensive driving and anticipation. 99% of what keeps me safe on the road is knowing what the other driver is about to do. You have to think ahead. Like getting into the exit lane a mile before you have to exit so that you don't "have" to jump over at the last minute and cut someone off to make your turn.
Some people are NOT naturals at this skill (my husband included) and it shows on the road. I was paying attention to the other cars and checking blind spots when other people drove since I was a kid (like, 10) so it comes pretty natural to me. Other kids don't pay enough attention to know how to get home from school on their own. You can learn to see when someone is about to pull out or change lanes in front of you and brake before it becomes an issue.
First practice driving in a parking lot, as suggested. You need to learn to operate the car itself on auto pilot. Meaning she needs to be able to physically control the car, use the blinkers and wipers and such without having to think about that. Then on the road she can focus on the traffic instead of having her mind on where the controls are.
Then learn all the common streets and intersections. It helps a lot if you know where you are going to have to turn ahead of time, or to know that you need to be in a certain lane before you are actually in the middle of it. Talk about it. Have her ride up front and pay attention as you drive around town. Ask questions like "where do I need to turn to get to
Walmart?" Or which lane will I need to be in at this stoplight? Make her think about it.
In my defensive driving course they made us say other things out loud too. Like, mirror checked, blind spot checked, etc. At stop signs you had to say "clear right. Clear left" before going. When approaching red lights you had to call out "point of no return" to indicate that if the light were to turn yellow, at this speed it would be safer to go on through it. They were making you think about and discuss your judgement calls out loud.
I think the book we got was called Driver's Ed In A Box, and it was a parent taught defensive driving course. My sister said it really helped her. My grandpa actually did most of the drive-along on the road stuff with me. He would ask those questipns, which lane will you need to be in up here? And make you think about it. My mom did a lot of the parking lot stuff and we made loops around non busy neighborhoods when the kids were gone to school.