In Britain, there's been an ongoing fooferaw over whether women in their 50s should be allowed to use in vitro fertilization to conceive children.
The first study to investigate the parenting experiences of older IVF mothers has revealed that they cope equally well with the stress of motherhood as those who have children in their thirties and forties, and are no more likely to suffer physical or psychological ill health….
The results showed no significant differences between the three groups on any of these measures. If anything, the oldest mothers [who gave birth in their 50s] suffered slightly fewer psychological problems than younger ones….
"Society still has these feelings about motherhood," [says Richard Paulson, one of the study's authors.] The way we view the mother is much more circumscribed than for the father: she should be young and attractive. That is underneath all this talk about the ethics and legality of treating older women. Deep down, society has a fixed idea of what motherhood should be, and this causes deep discomfort."
More here. The news stories I skimmed (haven't seen the study itself) didn't make comparisons between mothers in their 20s and I'd be curious what that match up looks like, though I doubt it would be any different. The researchers suggest that women in their 50s tend to be well off, in good domestic situations, and motivated as parent. The one caveat: The oldest children in the study were 13 years old, which means that the dread teenage years had yet to begin in earnest.