My first (successful) felting project:

I should have taken a before picture but it was a basic charcoal grey crewneck sweater from Old Navy. The thing was shapeless and made me look like a boy (well, with the obvious female parts). So I felted it and made a cute girly sweater that makes me look like a girl. Imagine that!
Right now it is fastened with 3 safety pins embellished with little black bows. I didn't want to make any rash decisions and end up with snaps or buttonholes I abhor so I figured this would buy me some time and creative energy.
One problem (which I hope you all can help to solve!): I shortened the sleeves but it seems they did not felt as solidly and I am afraid they might unravel more when washed. Any ideas? A simple hem? Blanket stitching? Can you felt just one area of a peice? Or am I just plain screwed and will never be able to wash it?