So it's in the developer's interest as well for the manager to figure out a way to reshape his/her job to make it sustainable (and thus keep the paychecks coming) rather than just saying "uh, sure, go deal with your problems, take as long as you need; when you run out of money we'll still have your job here for you."
Plus -- "first newborn in the house" is something that causes upheaval for maybe 6 months or so, and then life settles down again. If you have a supportive/flexible work environment then "up all night with a crying baby" here and there (before the baby grows out of that stage!) doesn't result in crushing stress and visions of disaster.
Edit for more context -- we have a developer who works part time and sometimes takes long sabbaticals -- switching into his alter-ego as a theater director. It's quite a different sort of situation from someone who has a newborn and is burning out.