I knit my sister's easter dress this year, and I'd like to knit her a sweater to go with it.

I'm looking to knit a ballet-style wrap sweater for a little girl in 2T size. I have plenty of yarn in my stash, so I'm open to suggestions for patterns in any yarn weight.

Thank you in advance!

These don't exactly wrap, but they're really cute and are the right sizes.
http://www.allaboutyou.com/craft/Knitting-pattern-baby-tied-shrug/v1
http://knitmepretty.blogspot.com/2008/05/gg-shrug-pattern-wip.html

Here's a few kimono type that have a similar look and probably be adapted for what you want.
http://cache.lionbrand.com/patterns/60128A.html
http://fortheloveofyarn.com/Issues/07Winter/patterns/winter07_kimono.shtml

This one is absolutely adorable. I don't know where you could get the book/booklet though.
http://www.sirdar.co.uk/designs/books/b346