There is plenty of evidence that younger women (<35) get pregnant more easily, have easier pregnancies, and have lower risks of complications. After 27 or so, the odds of it all going well start to decline. After 35, which is about when women would be trying for #3 or #4 if they started in their late 20s, those odds start getting worse quickly. No point lying to people, unless for some reason you want the people listening to have smaller families.
Of course, but you also don't want to tell young women they have all the time in the world to settle down. If they want multiple children, and by the time they're 25 they still haven't found a man they expect to marry, they really need to get on that.
I guess we're thinking of children along separate lines - I see it as a potential outcome of a good, stable relationship, but you're defining it as a goal, where the getting a mate is a step in the progress towards said goal. It's just a different way of defining relationships and lives.
I think having kids is a goal for a lot of people, e.g. the girl that is the subject of this thread.
>She has a career, and wants to get married and start a family sometime soon. Her boyfriend is a great person to be around and she adores him, but... he doesn't want kids (and is actually freaked out by them).