On my 7th b-day (when dinosaurs roamed the Earth), I got my first breadboard; that saved me from a career as a mathematician or physicist and a lot of money since I could easily reuse components. The experience of actually handling components and wires, making my own designs and calculations, that's the experience I want to give her (and her brother, who's now 5, so maybe start him next year).
I get the attraction of less grass-roots alternatives like snap circuits and Arduinos, but nothing like building your own circuit, testing it and playing around with actual components. I still have a lot of components and breadboards left at home from my old days, so she can have all that, but I didn't have my own oscilloscope or signal generator (built several) and only got a multimeter by the time I was 11. (Around the time of the K-T meteor.)
(On the books & study materials she'll get all my old stuff, plus a few modern books written by former colleagues who are still EE/CS profs. Even my Art Of Electronics, 1st international edition, solder burns on the cover and everything.)
Also, her uncle (me) might buy himself a new electronics "kit" for tinkering around at home -- a person needs hobbies and EE/CS is certainly cheaper than most hobbies. (Think golf or collecting bespoke clothing.)