Cochins are a pretty mild breed, but you shouldn't assume this individual cockerel will grow up polite without any training and discipline. He's already demonstrated a lack of natural respect for both you and your child so this is a red warning flag, and you should take the warning seriously.
I had a male friend that ended up in the ER getting 30 stitches on his leg from being spurred by his roo. Imagine if your child was spurred in the face, which is a real danger being close to the ground and half the size of an adult. Do not take the chance this won't happen.
A cockerel that has natural respect for humans will voluntarily remove himself from your vicinity, never approaching with a dance, never pecking you, always moving away from you and never toward you. Think of a magnet approaching a magnet with opposite magnetic poles, they actually move away from each other, never toward.
You need to examine your motives for keeping him. Is it important enough to you that you will commit yourself and your time to discipline and training over the next six months in order to have a rooster you won't need to worry about? If not, it would be best to just rehome or sell him now.