It might be easier and faster to define what a healthy family is.
Ideally a healthy family is one where each person is valued for who they are and who they want to become. Their ideas and feelings are valued and appreciate. They are encouraged and supported in whatever choices they make. From the time they are little and just taking their first steps healthy parents let them take that step, In fact they eagerly wait for it and support and encourage every effort to take that step even when they know the child will fall sometimes and get hurt. So the healthy family is there even when they know a child will make a decision that might hurt them.
Healthy families also help a child learn how to make decisions. No parent will watch as a child climbs up the front of a bookshelf. The parent sees the danger, Warns them, removes them from that danger and suggests alternative ways to get what he wants, like asking someone for help. In the healthy family the child learns that he or she is listened to and needed help is given.
The goal for the adults is always to respect one another even when you don't agree. And that respect goes down to the children.
Anything that stunts the development of the children or that belittles, demeans, instills fear and/or the threator act of emotional, sexual or physical violence is dysfunctional. It can be impossible to see when you are in it because if you were raised in it everything looks "normal". And "normal" is very subjective. It can even become comfortable because you understand the rules of that life.