Myra loves her birthday dress, but as an added incentive I made her baby doll a matching dress as well.
I couldn't find any free patterns that I liked for a 12 inch baby dress, and Simplicity patterns weren't on sale, so I decided to just draft it myself. I used the peasant top tutorial from indietutes. Her tute starts at a size 2 and is intended for a human, so I did have to scale it down a bit.
Vegbee's tutorial goes through the assembly so I'm not going to recreate the wheel here, but should you need a peasant top or dress for a 12 inch baby doll, there you have it! This makes a knee length dress on my 12 inch tall baby, with the ruffle it goes to her ankles. I imagine this pattern would also work for an 18 inch doll, with appropriate length modifications.