Most of the kids (and programming clubs) use some type of video game context to start programming (Codeacademy, etc.). I'm not convinced that's the best method, but a lot of people that understand education better than I do say it works. I think it's important to get professional tools into their hands as early as possible and let them tinker with them. Raspberry Pi's make great tinkering devices if she is leaning towards hardware or even robotics. She'll learn more about how computers operate on Raspberry Pi OS than using a Windows or Mac. Next steps would be a GitHub/GitLab account and learning how to use VSCode.
The language she learns doesn't really matter, but I'd probably recommend a scripting language to begin with, and Python has the widest range of applications right now IMO. While it obfuscates the fundamental computer operations, it will allow her to focus on concepts and thinking algorithmically. Save the low-level intricacies for college and beyond.