(I do these separately so you can delete later, if you like)

I've got some light britpicking for you. :)

They wouldn't have a backyard, they'd have a back garden (presumably shared with others in their flat-stack, so they'd probably only have a patch they could use for gardening unless others didn't want to bother with it). Molly also would have been plucking courgettes, not zucchini, though since that's in the narration and not the dialogue itself, I don't know if you'd want to fix it or not.

I think that was it. Nothing major, really, just little things. :)