I would keep her completely shielded from the limelight this election, as much as possible.
My bet is he will use her for photo-ops.
Already done. Today when Kerry and Edwards made their first joint appearance, Kerry made sure to point out the kids and that one of Edwards' little ones was being hoisted about by one of the big ones (I think one of Kerry's daughters). It did have a "DON'T MISS THE CUTE KID" effect.