Enter the Ikea fabric that I'd bought a long time ago. We are talking a long long time ago actually, like, in the Time Before Children. I bought it so long ago that they don't even stock it anymore. It's so cool though. I made the most basic dress I could, (which I've made before, here and here) and then let the girls colour it in.
After it was coloured, I sewed it up, iron it and washed it, as per the instructions (to set the ink). Now, Sophie has a kindy dress!