This is a pattern for a basic t-shirt size 4T (with or without a front pocket), and it would work for a boy or a girl.
What you'll need:
- About 1 yard knit fabric
- Small amount of contrasting fabric for collar (optional)
- Walking Foot (optional-if not using serger)
- stretch needle (optional-if not using serger)
- 1/4″ clear elastic (optional)
Take a look at this DIY Upside Down Pocket Tutorial, too.