The 13.

I remember the exact moment that it struck me. Alexander was underfoot in the kitchen after dinner constructing a miniature drum set from the pots and pans. I sighed wondering whether or not I could leave him alone to get ready without returning to a catastrophe.
My husband should have been home by now but it was just my luck that the night of my first concert he was late. I hurried down the hallway of our moderately small house, listening for the sound of his car. I told Sophie to finish up her homework to alleviate my conscience of the guilt that came with leaving the children to pursue my dream.

"I remember the exact moment that it struck me."

The moment what struck you? Why be vague at this point in the story? You're holding back information that we require as readers to understand your characters. This is a pretty big no-no.

"... our moderatly small house..."

Lose moderatly. Does it matter if the house is moderatly small, or modestly small, or slightly small, or spaciously small?

"I told Sophie.... alleviate my conscience of the guilt..."

Why does telling her daughter alleviate your MC's guilt? I don't really understand this, except in that you are trying to tell me something about your MC when you could do better by showing me through your character's thoughts, actions, etc.

All in all, I'm not really hooked here. I'd probably read a few more pages because it is technically pretty good, no major grammar issues. I'm also a little interested in why your MC's husband wouldn't be home in time to make sure his wife could make it to her first concert. I wonder why he's not going. I know if my wife had a first-ever concert and it was her dream/passion to play, I'd be there in a heartbeat. Maybe it's just the topic that isn't really drawing me. I'm not really hearing a strong voice here either, but that's neither here nor there. There is a bit of a hook here (the husband), but it doesn't do much for me personally.

Jayson Merryfield

I remember the exact moment that it struck me.
As a reader I don't like the "that it struck me," because I'm not far enough into the world to feel any suspense about what "it" could be. It's just annoying to not have you say "the moment the thought struck me," or something like that, at least. Also, do you ever tell us what "it" was that struck you, because if so, I didn't pick up on it.

Alexander was underfoot in the kitchen after dinner constructing a miniature drum set from the pots and pans. (I like this imagery, but I'd lose "miniature" because it's lengthy and adds nothing, I'd also like to see "from" replaced by "out of")

My husband should have been home by now but it was just my luck that the night of my first concert he was late. If possible lose the "it" and the "that" "...should have been home by now but just my luck the night of..."

I hurried down the hallway of our moderately small house, listening for the sound of his car pulling. (pulling what? a trailer? a rabbit out of his hat? I assume you mean pulling in or pulling up)

I told Sophie to finish up her homework to alleviate my conscience of the guilt that came with leaving the children to pursue my dream. This sentence bugs me, like it doesn't read true to the narrator, who, I assume, is a young mother (maybe 30 at most) who is leaving her at-home role to pursue a musical career (or hobby.) In any case she probably doesn't think in terms of "alleviate my conscience," there has to be a simpler way to convey that idea. Maybe I'm just being picky, okay I know I am, but that's still a touch pedantic.