Good song, you certainly have good writing chops, nice arrangement too.

As far as the vocal goes, first of all I really like her voice. Waves has a plugin called vocal rider that is very good at bringing up the quiet parts and bring down the loud parts. But there is one spot, around 3:20, where it is so loud it clips. Not much you can do about that, I assume that was at her end? If it was me I would be tempted to get her to redo it.

But yeah, another good song from you!