Late night thoughts while listening to........this discussion. I'll make it short and sweet. To my female colleagues and especially those trying to make the choice between a shorter tenure track and having kids. This is my view from the advantage of hindsight as a tenured prof with one child. If you want kids, do it when you want to, not when your department wants you to.....if this is important to you, don't put it off. I doubt if you will ever regret the time taken off, or all the ups and downs that children bring to your life. However, you might regret to find yourself at 45 without chillren. Maybe. Life is not the number of papers you publish per year, even if many people may try seem to live by these standards. Its many other things. Do what YOU want to do, whether it is the choice of the kind of place you want to work, the setting (a small town instead of a big city), the kind of research that excites you, work with the people that you like working with..... do it for you, and not for a system that rewards in strange kinds of ways. Have fun.
By the way, a partner who shares 50% of the load in all things, including the kids, makes ALL the difference as well. I'm lucky to be living with one : ) Alison Munson Professeure, Écologie forestière Université Laval, Québec