I used Burda 9608- its designed for girls size 7-12. I measured Elizabeth out as a size 11 in most places and a size 9 for length so I cut out the size 11 but made it shorter. The finished dress is quite roomy and she will get this season, and probably next out of it. Its really quite a straight forward pattern- there are only 4 pieces and the only variation to the pattern is the dress length. It DOES have a side zipper though, and quite a bit of bias binding. However, if you think you're ready to give a zip a go then I think this is a pretty good pattern to try. The rest of the dress is super simple and the results are really nice.
I bought the main fabric at spotlight just last week, its a lovely soft pick cotton with floral love hearts and a scattering of butterflies. I made the bias binding myself using a black poldakot quilters cotton (I dont remember where I bought it, but its not hard to find in places like Etsy or spotlight or a good quilting store).