Dusting off the crafty hat:
A pillowcase dress! Doesn't that sound fun for a little girl? Plus, people are paying beau-coup bucks for them on Ebay.
Why not? It sounds easy.
First, read this. Then get the template from here. Then realize you don't sew. Unh-uh. You don't. Well, hell. But wait! They make glue for this, don't they?? Resolve to make a nearly sew-less version.
Then find some pillowcases you can cut up and not feel badly about. Suggestion: do NOT take the ones off your bed. Your formerly oblivious-to-linens husband? Will notice. Damn his eyes.