We've been thinking about this a lot too. We're currently at a point where I can either keep working full-time for the next 5-7 years, and retire fully, or I can shift to half-time, and retire at 60. There's also the possibility, depending on a combination of luck and decisions about my partner's career, that I could go half time and the increase in his income will mean we could still retire early - but that won't be knowable for another few years. I've had the opportunity over the last few years to take two long periods of maternity leave, with a couple years work in between.
The first period of maternity leave was a burnout cure - I'd just paid off $50K of debt (run up in my name by my ex without my knowing...) in two years, mostly by taking a high-paid job I knew would be unpleasant. I returned to work with a much more FU attitude, although not exactly what I'd call FU money, and as a result was able to negotiate much better working conditions. Still, there were several moments where I wasn't completely sure I wasn't going to walk of the job, particularly as our accessible savings increased (before running into this site, I had been tucking all savings into retirement accounts - unlike the U.S., those savings are entirely inaccessible here until I turn 60).
I was much less burned out going into this period of maternity leave, and have therefore been able to enjoy the period mich more, and be more deliberate and active about how I approached it. The result has been that the period has been a lot more like FIRE than anything I've experienced before - and I've told my partner that it's going to be really wrenching going back to work, as I enjoy it so much. But I'm our main income, and we're not at the point where I can't go back at all. The part-time option really appeals, but will massively reduce our savings (and I have a secondary worry about how well my employer will respect the part-time hours, instead of paying me part-time for something closer to full-time work). I have the right to return part-time after maternity leave, for up to five years actually, without losing my entitlement to return a full-time position if I want. I'm just trying to work out whether to pull the trigger...