Well, if leisure time is time off work, whatever your work may be, then a root canal would, strictly speaking, be counted as leisure time. Possibly 'free time' is a better expression. There are all kinds of things one does in one's 'free time' which aren't exactly fun things, but you need the time off in order to do them. Working people who are not parents use their time off work to catch up on things like housework and grocery shopping and doctor appointments and catching up with family members. It's not like non-parents work 40 hours a week and the rest is all play time - but when someone does paid work, they often do tend to count time off work as 'free time', because the divide is more obvious.
I think it gets kind of complicated when one compares parenting with paid work (and I'm saying this as a non-parent, so all you mums can disagree if you think I'm off base!). On the one hand, parenting is very hard work, but on the other hand, it is a personal decision, and part of one's personal life, and so I would imagine it's kind of different, mentally, from the kind of 9 to 5 work where you go and do a job and get paid and come home, because it's you're life, your fulfilment. You are not doing it for money, but for the personal fulfilment of having a family. And the boundary between work and leisure must get blurred, because most mothers actually get deep pleasure in interacting with their kids, and so while a lot of parenting is boring mundane hard work, surely quite a significant amount of it is deeply satisfying, and a personal fulfilment thing, and quite different from the kind of satisfaction you might get from a paid job.
For instance, when I go to work, I can feel satisfaction from working with a client and making a positive difference in his life, but at the end of the day, that client isn't part of my personal life - we have separate lives, and what I do at work is quite separate from my personal life. But if you are a mother making a positive difference in your children's lives, then surely that is not simply a job, but it's developing your personal life, because that child will (hopefully) be in your life forever, not as a client but as a loved and loving family member, and you will have many enjoyable leisure times with this child in the future. So surely your work is also your personal life - the two become merged, and so it must be quite hard to separate your life into work and free time.