I used the pattern Lacy Baby Frock by Lisa Gentry from the July 2008 issue of Crochet Today, but the pattern only goes to 24 months. I did a really simple upsize by just using a bigger hook and heavier yarn. This particular pattern worked really well for that and still looks absolutely adorable. I plan to make one for my older daughter at some point, but I'll have to do a little more modification to make it fit. It should be easy, though, since the pattern is so well written and simple to modify.
She didn't really want me to take her picture because she was too busy playing in the back yard, so I had to catch her on the fly. She is without a doubt an outside girl...she loves to put on her rain boots and head out to the garden to find worms after it rains!