The best way to help your child is to have cycle training and teach your child yourself. Now most adults think they do not need cycle training, but they do and you will not be able to judge whether or not your children are riding correctly unless you  either have cycle training or read widely around the subject, e.g. books like Cyclecraft (which is like a textbook for cycling).
The reason for incorrect/unsafe cycling is that it can seem counter intuitive. It’s not about keeping away from cars. It’s about being seen by the vehicle behind and sometimes controlling the behaviour of the driver. We control the behaviour of the driver behind by getting in the way.
Now clearly, being able to judge the speed and distance of the vehicle behind is a skill that adults have perfected. Some very small children do make good on road decisions, and some older ones don’t. Occasionally adults can be poor in their on road decisions, but mostly adults understand traffic well.
Once upon a time children in year 6 got level 2 training, which was well suited to their ability. Then it was decided in an ambitious plan that it would be good if, year 4 would get level 1, year 5 would get level 2 and year 6 would get level 3. Having training for three years in a row is a great way to reinforce the learning. Children forget and having a refresher course brings it all back. This worked very well in the few cases where it happened. But it did not happen, the experiment showed that this is the idea way to teach children, but that once a child has had training on the road once, it was seen as enough.
So year five have level 2 before they are truly ready and year six do not get level 3, or any cycle training. And do not even get pushed to do extras or busier roads at level 2. Cycle training is seen as something children do, not adults and teaching it younger and younger is perpetuating this myth. Ask your self, if you are fearful of the roads, do you not need some help in cycling them. If you can not cycle you will not allow your children to.