Very cute marker work! I love the concept you have come up with and how creative everything in the background is!
As a critique the main thing i would say to fix here is that none of the colors have a darker shading to them. There should be a higher level of contrast (light vs dark) in the image it will define your shapes better and make it stand out more. Every area you color hair, cloths skin etc. should use at least 3 colors a base a shadow and a highlight. I can see you did a great job of this with her skin but i would have liked to see more shadow in the shirt.
In addition, you have used white highlights beautifully :3 the only thing i would change is to add one or two loose strands of hair with the white, this will define your image but not conflict with your current style.
You mention in the artist comments that you have trouble with scanning. Always scan the image at 300dpi or higher and edit the contrast and levels in photo shop. that way even if you colors get lost in scanning you can bring them back to life! great work and i look forward to seeing more from you!