Hi Belle
I've read The Phoenix Hunter over briefly, and have some comments.
I think it's very vividly imagined - there are some places where your descriptions really bring it alive. It's little things like the mum moaning when he insists on keeping the suitcase on his knees the whole journey back, or the windows being nailed shut in the hotel. Ironically, because your descriptions are so vivid in some places, it makes it more obvious when your descriptions feel rather skimped or too conventional - when you describe the bookshop, for example, it seems to be to be rather a stereotype of a bookshop, not a 'real' bookshop. And would Jack know about Dickens' London so he can imagine that the bookshop is like a bookshop in Dickens' London?
On the whole, though, I was pretty impressed. I do think it's worth working on.
One thing that really lets you down, though, is inconsistencies in your grammar, and I suspect this would stop an agent or publisher taking you on at the moment. You confuse 'it's' and 'its' a lot. Also, you tend to string sentences together with commas, although you clearly know how to use punctuation perfectly well, as in the next sentence you'll be using a semi-colon or a colon. I think that you need to iron these out, as at the moment, it comes across as less professional than it otherwise would.