So there you have it! A handful of YouTubers who are great for young gamers. Of course, I've only skimmed the surface here; there are many others out there who would be equally suitable.
If you are unsure as to whether or not a YouTuber might be suitable for your tween to watch, then have a look at the list of videos the host has uploaded to see what games they are playing. Obviously, some games are not suitable for children of any age, so you'd probably be right in thinking that they wouldn't be very child-friendly. You could also talk to your child to see what games they are interested in, and do the legwork for them by searching for suitable YouTubers yourself. At least then you will know who your child is watching!