It's a very pretty little house, with really gorgeous views. I really like it.
I think the kitchen would look prettier if the red walls were painted a rich cream, the cabinets are a lovely colour though. Also I would make a little curtain to attach to the counter under the stairs, hiding the small fridge and storage, either in the same cream as the walls or in gingham (or other simple pattern) the same blue as the cabinets. You will probably need to make a separate small triangular curtain for the bit under the stairs on the RHS. Also take the bags off the hook on the door and hang a single apron there, in colours that tone with the room.
In the bathroom just painting the dark green wall white might make a huge difference. Personally I would paint all the walls white except the one behind the bath and sink, it would look lovely and clean and make that green look spring-like.
Can you store most of your books elsewhere so the books in the sitting room aren't so stuffed. Also, if possible, it would make the room look much bigger if you could remove the two dressers and cd shelves at the back and store all of that somewhere else.
Is there no way at all to have a bannister put on? The lack of one is going to put off families with small children, which knocks out a big section of your target market.