Precedent has to do with interpretation of laws. We do not have laws that govern every little aspect of parenting. So a lot of what parents do to or with their kids is not under the purview of the law.
As to judges—they can always be overturned by a higher court. Cases work their way up to the highest court in the land: the Supreme Court. Decisions made by the Supreme Court can not be overturned by anyone else. However, the Supreme Court can overturn itself at a later date. This is rare, but it does happen. Usually they don’t say the prior decision was wrong so much as that the interpretation of the prior decision needs changing. It’s subtle.
In any case, precedent generally means that current decisions will follow the precedent set in prior decisions. Except for the Supreme Court, all other courts must follow precedent. Only the Supreme Court can change things around. However, if a lower court changes things, people can argue that they didn’t follow the precedent all the way up to the Supreme Court.
There, a prior decision could be overturned. Thus law stays current. It is flexible. This can be frustrating for folks who want things to be decided and stay that way forever. But it is good for society, because it allows past wrongs to be corrected.