Hi. Just from my experience, left/right handed has never made any difference to learning. Regarding maturity of six year old, try her on the animal notes version of this. I've taught many four year olds and even the odd three year old with attention span of a gnat and had much success. I also use it with adhd students. For older children, use the blank notes edition. Make sure you use heaps of other material in lesson also. Flash cards, "dozen a day" pink book?, " Theory made easy for little children"? (Stickers, colouring in here). Write the notes (not notation) for easy tunes they might know and can play. Or copycat games, just copying you playing.. keeps you from going nuts also😉
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