Pauline is the girl Mario tried to save from that DK in Donkey Kong for the NES. Pauline also appeared in the later Mario vs. Donkey Kong 2: March of the Minis and it's sequel, Mario vs. Donkey Kong: Minis March Again! Pauline is not related to Princess Peach at all, except that they have both been kidnapped and rescued by Mario.
Related ThreadsHow fast would Pauline's heart beat if she was in space? - last post by @ Nov 18, 2008
Pauline? - last post by @ Oct 28, 2003