Traxxas Stampede is probably one of the best beginner RC.
I'm not trying to sell you on Traxxas but nobody does RC better for the casual RC hobbyist and the Stampede ticks all the boxes for a 9 year old and parents.
It large enough to use anywhere. 1/10 monster trucks are king bashers. Anything smaller (smaller than 1/10 or 1/10 buggies, short course, or stadium trucks) and you'll have trouble on grass until you get into big power brushless motors.
It's fast enough to jump stuff and have fun. It's slow enough to be controllable.
It's durable. Bash it hard enough and you'll break it, sure, but the combination of slower speeds and durability makes that pretty rare. Electronics are also waterproof and warrantied.
Parts are available. This is key. Most inexpensive RC you'll find are gonna be one-off Chinese junk. Where do you find a control arm when it breaks? With a Traxxas, you go on Amazon and a new one shows up tomorrow (maybe you buy a stronger one because everyone sells hop-up parts for them too).