Things get all screwed to Hell if it doesn't happen like the above (Re: Love). Ok, it's natural for young women to want kids. It's kinda cute actually. But uh... there really is little difference between women wanting kids without the context of a marriage/relationship/love and men wanting sex without the context of a marriage/relationship/love (pure Western culture, there are other parallels for other cultures or hybrid-cultures). They're both biological desires or urges. Think about how totally mammalian that is... males wanting sex, females wanting offspring. It makes sense. In fact, just as how a woman will attribute her biological urge for children to something spiritual (indeed, the selfnessness of raising children is spiritual, but it's something even animals... without souls... do), a man can also 'spiritualize' his sexual appetite (as in... it's human nature to want to mate... and simple mating can be spiritual, but just because a spiritual context is thrown on something, does not make that very thing spiritual at all. it has to be effected from within, not without).
What is a child really? Not yours, Khalil Gibran would say who I thought had the best quotes about them. What a child really is, is all that stuff from above. It's everything. An expression or manifestation of love and faith in the union more or less. Just as that's what sex is really supposed to be for people who pursue existences higher than simple animals, it's a perfect way to express love, and having a child together and the act of raising it is an even more perfect expression of love.
Raising the child employs full use of the 'mirrors' of all parties involved. Because the child is an altogether different person from either of the parents. It's a seperate soul. The selection of that soul might be based on Divine Wisdom, so it might be similar depending on circumstances, or it might be completely different.
"Your children are not your children:
They are the sons and daughters of Life's longing for itself.
They come through you but not from you,
And though they are with you, yet they belong not to you.
You may give them your love but not your thoughts,
For they have their own thoughts.
You may house their bodies but not their souls,
For their souls dwell in the house of tomorrow, which
You cannot visit, not even in your dreams.
You may strive to be like them,
But seek not to make them like you.
For life goes not backward nor tarries with yesterday."
Anyway, the love of parents. It goes without saying a child needs parents that love it, and also love EACH OTHER. Ok, maybe it doesn't go without saying. Parents who love each other (outside of the scope of religion) will usually have kids that are pretty decent in worldly terms (the spiritual correlation is a different matter). The 'complete' expression in this method would be love predominating between the parents-to-be, and funnelling into a love for God. Often, the sure-fire way to insure that happening (cuz love isn't storybook for most people) is to do the whole union for the sake of Allah, by having sincere intentions and right actions (using only Deen itself as the major criteria when finding)... you love Allah, so you love doing what Allah orders you to do, and marriage being half the religion insures the partners will be in a state of perfect/pure love regardless of whether or not they even sensually love each other because love and faith can be converted into each other like currency. And this is important to note, because in an Islamic atmosphere (sometimes zero contact between husband/wife before marriage), love cannot happen before the marriage and is almost purely the result of the conversion of the Faith poured in. And you see that before you as something that works. You can't see Faith? You can see love in these relationships. All of that came from Faith. That isn't to say that will wind up being the best marriage, but it definitely has the best set-up and the most optimal chances because of how close it's linked to faith.
Parents who don't love each other have weird kids. You can have an absentee or horrible father, and a mother who completely dotes over her children because they're the only love left in her life and likely they'll grow up to just throw all that incredible spoilage back in her face without any gratitude. That's freaking horrible to just think about, and that happens all the time. Thank God though that children are independent souls, and it could be that God allocated a soul destined for awakening in completely random environments: "The wife of Nabi Loot was an unbeliever/ While the wife of Firaun was a believer./ He brought forth from a temple of idols, a Siddeeq/ And in the Kaaba was born a Zindeeq (Abu Jahl)./ The son of Azar (i.e. Ibrahim (A.S.)) was the friend of Allah/ And Kan'aan, son of Noah, was gone astray."
Buuuut, all of that, that's not something people usually think or feel. They just do it, and if their hearts are open to it, they reap the spiritual benefits of it. If not, they just further the human race. Which in and of itself is a sort of worship as I said before, since simply living is a reflection of a Divine Attribute. You know how they say everything does dhikr to Allah? That's how. (This is probably the most profound branching-off point of any idea here, but I'll stick to the love stuff). That's why the structure for marriage is laid out in such detail in the Qur'an... it provides the optimal atmosphere for that kind of 'worship' of Allah. All of what I'm writing here are feelings translated into thoughts for the purpose of discourse. You don't have to think this stuff, you FEEL it. An idiot can be in love and have/raise children. But the problem nowadays is the lack of that very feeling. You can't force people to FEEL it the right way. And just like other matters, doing without feeling is common. That's why I find it not surprising at all that 'liberals' in Western society are all for the disintegration of marriage... they're the Wahhabis or Salafis of the relationship-world. After all, the same Western principles of 'liberalism' are what gave Wahhabis/Salafism the chance to emerge onto the Islamic scene recently.