Good advice for parents there.
But why make a 'minor battle' out of what could have been a learning point?
e.g. tell them that peoples names always begin with a capital, but are usually written with small letters after that, and agree that you'll let them write their name how they want (it's their name after all), but you'll write it the more usual way.

Other words mean the same if written in upper case, lower case, italics, cursive etc etc and they have to learn that sometime.

I helped at a Girls Brigade years ago and had difficulty stopping myself correcting the spelling of Debra, I'd only seen Deborah up to then.