I don't understand why all these comments are against web dev. Creating an html file is quick, easy, and most importantly for kids, you instantly get visual results! You don't even need to open ugly terminal consoles, you could just use something like JS Bin (https://jsbin.com/) or JSFiddle or CodePen.

I used to volunteer with CoderDojo, a non-profit that hosted intro to coding workshops for kids of all ages (including 7-year-olds). Maybe you can find something like that local to you? I don't know if the organization still exists, but this is one of the lesson plans we used, which I think still holds up today (except the last part, you don't need jQuery anymore lol):

https://github.com/CoderDojoSV/beginner-web

I also came up with my own workshop as a follow-up, specifically about creating fun shapes with css:

https://github.com/heidid/css-art-workshop

I remember the kids also enjoyed trying out Inspect Element on existing webpages – I joked that you could pretend to change your grades to A+'s (temporarily of course), though hopefully grades are not of concern to a 7-year-old yet :)