You are getting better. I quite like the dog's mouth and the little details, but you should try to get something to do straight lines for the book and such, it screws the perspectives.

In the first frame, I would definitely say the back line of the table your climbing up on is crooked. The scene also feels tilted at a angle for some reason and I think its because the lines on the shelves though appear to be straight are running at an angle. My biggest gripe though is the floor and wall coloring, you shouldn't have used to blueish colors for both a wall and floor as it cause them to blend in to much and imo makes the picture look bland boring.
one thing I did like in this frame though was the way the claws and paws turned out.

Second frame: Definitely like the tan on dark blue floor (Table) and wall coloring as it helps to break the to colors up and makes everything more lively and natural looking, imo. Only thing that really erks me in this scene is that chat bubble, for some reason the wasted space as the bottom bugs me. Overall not really anything i truly dislike about this scene and its definitely my favorite of the first page,

Third frame: I agree with Koinu-chan in that, the odd angled lines mess with ones sense of depth perception.

Overall: Only thing that i'd could still use some work is the hair, something just doesn't look right about it. But aside from that it looks good.

Sorry if this comes of as harsh, wasn't meant to be. Not particularly good as trying to provide feed back on artwork.

" My biggest gripe though is the floor and wall coloring"

Colours are really not my thing, Deuteranomaly colourblind so things will unfortunately appear odd, they look good to my eyes and i usually try get people to ask, "hey does that look okay" and nobody mentioned any issues.

I felt it added to the mystical witch-style of the room