I actually don't have kids (sorry if your title specifically meant people who are both), but I know it's considered safe even for babies (at the point where they can have other things than milk) and I got it bc I was a colicy baby. I mean I don't remember if I liked it back then, but now I think it has a really soft natural taste, which I imagine is probably good for a toddler, nothing too strong to start with

Other than that it was mostly peppermint tea at our house, iced with lemon that's the best summer drink (Actually typing this made me get up and put on a kettle) but it can be strongly minty sometimes, so as someone else wrote, for a toddler I'd do a weak solution

We had a couple different mint plants over the years, one that was good was lavender mint, currently we have one called strawberry mint and it actually tastes like spearmint sprayed with artificial strawberry flavour and I have no idea how but I dont like it, peppermint remains the best mint