In my opinion, people are ready for marriage whenever their mind is ready. The ready mind means an adult mind. The adult mind is different from a child or young mind because they find something more important than playing and hanging out whit friends. Being an adult does not mean over eighteen and id does not relate to age actually it relates to our knowledge about life and important things in life. their age doesn't say anything because as we see in society some young people are related to their parents and they can't live alone, so still, their parents take care of them, but marriage doesn't mean taking care of each other like a child, it means help other to be more complete than before. So age doesn't say anything and people's imaginations about marriage tell they are ready or no.