If the mountain you are referring to is Taranaki, yes, more than one. Of cause you can go there with children. To go up to the top, you need to be fit though.
If you check out my list of previous posts @artguru, you will see I've done a whole series of our trip through Zealand. To make it easy to pick out the New Zealand posts in my list: each of those posts has the same icon image as at the top of this above post.
In a couple of those posts I did a write up on Taranaki. I was called upon to paint two oil paintings of the mountain, so was taking photos of it from different angles. And one day was take up the side of it.
After one or two more trips on the north island: I'll post blogs of our trip down to the south island, and traveled right down to the bottom point, and then traveled back a different way. So that will be coming soon. I try to post my posts on New Zealand on Wednesdays.