Dang Crosby, you got TWO send-off episodes, and an ingenious way of bringing you back (albiet 20 years older)...
Personally, for Nemesis, I would have had her appear to Picard in silhouette (echoing her first appearance) to warn him of this, that or the other. And that would be it. Not a big role, but a little nod.
Or barring that, could have even made her Nero's dead wife...but that would have been a bit much maybe.