What a cutie!
There are many online tutorials on different ways to turn a men's shirt into a girl's dress but most, ok all, give measurements for little ones. The biggest I have seen is a 4T size. The concepts are the same though and since Grandpa was quite tall this worked out to fit my Abigail just fine
|Are we done yet Mom?|
Here you can see some of the detail. The front of the shirt became the back of the dress. I kept the original shirt pocket because it's just so cute that way.