So yesterday I got a cornet. I used to be in a band, and a local one has roped me in, so I was practising to get myself up to speed. DH had a go and got a kind of note out of it, DD2 put her mouth near it and then cried because it didn't make a noise (she is only two
) Then 5yo DD1 had a blow and did a lovely long, clear note. 
Now she wants to learn. I know that there isn't much point in her doing too much learning before her adult teeth come in, but I showed her some sheet music and she was very excited at the idea of learning to read it. She can already read words very fluently, so I think she likes the idea of learning another type of reading.
I don't want to be pushy, and it's not like she will be a child prodigy, but if she is interested in music, I don't mind teaching her. My entire family has been in brass bands at some point and I would love the DDs to be able to read music.
So, what do I need to be careful of so I don't tell her the wrong things?
She has also picked up our guitar and ukelele, but I will admit that I don't really know much than slow chord change...strum...peer at music...slow chord change...