I recommend getting kids to touch type as soon as they understand written language. Here I want to argue that it's best to get them started on Dvorak layout right away, skipping QWERTY entirely.
- Children's little hands with short fingers are greatly aided by concentration of frequent letters in home row.
- Kids these days have wrist problems (mostly caused by phones). Dvorak layout reduces wrist strain.
- Use of AltGr key to pick letters from national alphabet (as opposed to fully specialized national layouts more common with QWERTY)
has a number of advantages:
- It supports mixed English/national use, which is much more common in globalized world. This comes at the cost of harder access to national alphabet, but this downside is offset by better overall keyboard layout.
- It preserves access to full symbol palette when coding.
- AltGr combinations for letter variants are easier to learn, because they are usually located on base letter key.
- Dvorak layout is faster to learn and allows faster typing.
There are two well-known downsides of Dvorak layout:
- Shortcut keys are sometimes in weird places. This is however imperceptible for children who never used QWERTY.
- Hardware is harder to come by, especially when it comes to child-sized keyboards. This is less of an issue for skilled touch typists who don't look at the keyboard.
I nevertheless recommend Dvorak layout as the first keyboard experience because of the above mentioned advantages.