I would try to find an advanced dirt school for her.
Better to let her learn on a track or trail than risk a fall on the road.
One of the first times my wife had to pull her bike from the pavement to the dirt she grabbed the front brake at walking speed.
Front wheel was turned and down she went. Bent shifter and nothing else hurt on her or the bike.
There are so many little things that we learn over years of riding (and falling) that we don't always remember to tell someone who is learning to ride. I know I am a horrible teacher.