Children often mirror their parents, it’s not unusual for a child to support the same club as his/her parents. This is often the case until they reach adolescence and are able to make certain decisions for themselves. Their views on sports, politics and other topics might change as they become more aware of the world. It wouldn’t be right then as a parent to force your kids to support your own ideologies. Moreover, a true football fan knows that club loyalty cannot be forced on a person.
Another interesting question is this, as a father would you force it on your child to also fan the same club you're a fan to, or you will allow him be himself to fan any club of his choice even if it's your most rival club of all