This is charming already. I like Hellen. She reminds me of myself in some ways; I write things in my head, as well. I'm curious to see the journey she embarks on.
I can't really critique anything, considering this is only your first chapter. I do hope you add some more of her backstory to the mix, though, because they're always interesting to read.
It'll also give some character growth and development, as well as explain why she has depression. Or, maybe there's not a reason for it.

Anyway, kudos to you for a great chapter so far.