First of all, your art is beautiful! I'm sure plenty of people will want it when they get to see it!
A few things I would do if I was you:
1. Have more shop items - the wider your net, the more fish you'll catch!
2. Fill out your description a bit. Explain things like - what kind of paper are you using (for example I use 315g 100% cotton paper), what inks you use, (again I use Canon archival inks which are reportedly 30 years lightfast).
3. Make your title more SEO friendly - for example, with this item
http://www.etsy.com/listing/104117936/colorful-deer-and-fireflies-print-9-x-15 I suspect few people will want to search for 'Colorful Deer and Fireflies' I'd be inclined to use a phrase such as 'Illustration Print' or 'Children's Illustration Print' or 'Children's Art Print'. It'd be worth experimenting with a few different phrases like that and seeing which works for you.
4. Consider using main photos with a white background. You could use
http://fotofuze.com/ to clip the background out of your existing main photos for free. The reason for this is that they're more likely to be included in treasuries if they have a neutral background and also far more likely to be in a front page treasury too.
5. Join some teams. I've found that team membership has been a great way to promote my shop - it's a two-way thing. You all work together to promote each other.
6. Keep trying - different things, new things, etc until it starts to work for you.