What do you mean by saying that It is good for a young lady to get married before marriage? I can't really get your point but i will try to resume key ideas: It is important for any man and woman to be in a relationship for a sufficient period of time before deciding to get married. I emphasize that this should be before the decision to get married, not the decision to have a child. In Eastern societies, we call this the engagement period, which precedes the step of marriage. The engaged couple spends this period getting to know each other better and experiencing some shared experiences so that they can become accustomed to each other's personalities and determine whether they can continue. Then, after making the decision to get married, they take the time to make the decision to have and raise a child. This is a logical and sound approach, but what happens in many societies is that the decision to get married is inevitable due to having a child during the dating period, without either party wanting to. This often leads to deliberate neglect of the family and children, especially if they continue to have more.
I know exactly the eastern societies, but engagement period is actually a step where both of them are sure they will get married, it's no longer a selection step. From what you wrote, engagement period is like selection step where both of them are still not convinced yet.
There's another way of "knowing each other" in Islam, where both of them not engaged, but they're approaching each other with their family. Usually both only know each other for 1 month - 3 months which is crazy I think, you won't know the real character if it's that short.
Although having a relationship is haram, but it's better because if you both already know for many years, high likely you both already reveal your real character.
The close proximity between families in the establishment of marriage is a negative factor in Eastern societies. This closeness prevents partners from fully understanding each other's personalities, including their suitability for the responsibilities of shared life, most importantly childbearing and childcare. Evidence of this is the disproportionate number of divorce cases in courts, particularly those involving child neglect and irresponsibility.
I'm not saying this only exists in Eastern societies, but rather all societies with cultures that condemn relationships between the two sexes outside of marriage. In such cases, the powers granted to families exceed what partners can exercise within a partnership. Partnership before marriage is a partnership between families, not between the two parties who will bear responsibility later on.