1- There are people who are above 30 and still don’t know who they are, what they want and wander around for a perfect match. Right?
2- Yes finishing education is important.
If the man can support the family and girl can still go for ‘useful’ education then this scenario still is better than both waiting for a high advanced degree (a piece of paper with no good job), losing precious time to enjoy married life and then when getting old with wrinkles and fixed mature thinking, trying to join gym to keep in shape with joint pains, and then getting married and trying to enjoy children.
Many stop after one child don’t they? since its just too much for them to deal with at later life.
I am not strongly supporting 18 year old girl to be married but there are lots of positive which older couples do not get to enjoy.