About a year ago, Jean Twenge wrote this fascinating article in The Atlantic about how the information that most people use about fertility and age are based on "statistics from a time before electricity, antibiotics, or fertility treatment". Furthermore, the article points out that these studies are not only based on relatively small, homogeneous samples of women from 1670-1830, but that these studies are also poorly designed. In this article, Twerge thankfully sites a number of modern, well-designed studies that paint a far more optimistic picture about female fertility and age.
Clearly, it would behoove everyone, particularly the aforementioned "well-meaning advisors" to read up on the current statistics on fertility and age. It would also be helpful to understand that what may feel like helpful advice (which, seems to be based on dubious data) might put unnecessary pressure on a woman who may already be struggling to define her place in society, in the workforce, and as a self-sufficient and whole human being. Not to mention that being pressured into making a decision that is as life-altering as having a child is likely the least beneficial way to make it.