It sounds to me that you're assuming leg up sentiment is in relation to professional musicians while the author is relating to herself: someone very bad at music (maybe because of lack of exposure to it during childhood).

I certainly wish my parents cared even a little bit for music and sounds. I didn't encounter the idea that sounds have names or distances between them make melodies until primary school. Music wasn't playing in my home and no one sang to me. As you can imagine I am hopeless when it comes to music. I can't even sing a sound I've just heard. Not even close. Her children definitely have leg up in comparison to me.

If I wanted kids I would be happy to encounter the article. Maybe I could save my children from the fate of musical tone deafness.