This pattern has a size range of 6 months to 14 years. I chose size 3/4 for my girly girl, only because she's quite narrow. Good thing you can customize the dress and sleeve length very easily with this pattern. It includes several charts to give you a guideline, along with whatever measurements you've taken. I love those charts, because my "model" is often at school or in bed when I have a chance to sew and I tend to second-guess my measurements anyway!
I chose to use contrasting fabric for the sleeves and ruffle along the bottom hem. Really, the sky's the limit with customization here! The dress I made below was done with the bell sleeve with ruffle option, but I did lengthen the ruffle by a few inches for extra drama. It's important to note that this pattern does not require a zipper...there is only one simple elastic casing to deal with along the neckline. Truly a fast sew! But I must add that when I sew this again, I will baste down the facing before sewing the neckline casing seam, just to ease the insertion of elastic later. I found that the facing created a kind of pocket that my fancy elastic inserting tool (AKA safety pin) kept getting stuck in!
If you're sewing the Leighanna and have any questions, don't hesitate to comment on this post and I'll help in any way I can! This pattern would be perfect for a sew-a-long and to fill out a young girl's fall/spring wardrobe. I already have another one in progress for my daughter!