I recently graduated from high school, and have some experience with programming in a middle school/high school setting. However, at the moment, I cannot recall much about when I was 7 years old, so I might have high expectations here :)

I believe it's probably most important not to force your kid to do anything and just guide them in a direction and let their interests shape what they spend their time on. Most peers my age grow up with a pure dread for math and science disciplines because it was forced on them throughout their whole life. For me, it's still painful to think about anything related to chemistry/world history because I just remember a sure dread while taking the course (although that probably had more to do with the course/how it was taught than the actual content).

I don't think Python's Turtle is the best way to go here because it is difficult to build on the skills learned while mastering Turtle. Plus, nothing that will be built ends up being that impressive (whereas HTML/CSS can make awesome things). Scratch is probably a pretty good way to start just to get them to think about how specific problems could be solved.

For beginners, and kids especially, it often works great when you can build something concrete and show it off to people. Here, HTML and CSS will work great, since they are super basic and will produce real-time feedback. HTML/CSS can get you pretty far when building a website, but then once they begin to question how to do more difficult things, it may be a good time to introduce JavaScript, just because it can talk directly to HTML/CSS and there will be an element of realtime feedback. With HTML/CSS/JS, I recommend checking out Electron (which is a framework to create desktop applications in HTML/CSS/JS) and looking at how to publish a site online (e.g., Github.io/heroku for free sites or buy a domain from Google for ~$12). Similarly, it may be beneficial to check out Swift and Xcode to develop iPhone applications. Swift produces a bunch of entry-level material and they have a nice drag-and-drop user interface, which helps visualize things.

If they're super into science and math, it may be beneficial to play with Mathematica.

If they're interested in games/VR/AR, check out Unity.

Beyond that, I follow the new-crowd here and would start with Python. The syntax is much better than other languages and it captures many of the most important features in programming languages. There is also phenomenal support for Python packages.

Good luck!