This is soothing. I was writing this post as I was listening to it and the first thing I thought was it needs more instrumentation. Maybe add a piano or guitar...BUT, then you pulled the piano out to lead!
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Now after listening to it 5 or 6 times I'll give a better review.

Ok, so first off you do express the innocents and even the emotions between the two characters, however I'm not feeling the pain and grief he must be feeling knowing that his sister who he loved is in another time. Though the piano does give me a taste, I'm not quite satisfied.
The melody itself is developed, but not really enough for a character theme. Usually people are rather complicated, but I think it depends. Will this only be representing the relation between these two characters or just Laura in general?
Still, not a bad piece. Just work on that pain and grief a little more.
Off-topic: What happen to that piece you posted in the writers forum? I think you had something there...