For those that don't remember the exact events of CVRPG IV (which is fair since it's a different section of those grand comic -- CVRPG vs DSWC -- and it was also a couple of years back at this point), the girl is Cassandra Belmont, early member of the vampire hunting clan who stole her brother's whip (the Vampire Killer) and went off on her own to fight Dracula. CVRPG IV is a good story and you should go (re)read it from the beginning.

The end of that comic had Angel taking Cassandra and Jenny back to their own time period (for reasons best left to you reading the whole arc again), so that's how Cassandra knows Angel despite her never showing up here in DSWC before. Man, I love making overlapping, complicated arcs.

 
    

When evil spreads across the land, and darkness rises and the monsters roam. When the creatures of the night make beautiful music, and the things that go bump in the night go bump with greater enthusiasm. When the world is in peril and is in need of a hero...

These guys are, sadly, the best the world can hope for. These are the adventures of the heroes of CVRPG. They mean well, they try hard, and occasionally they do the impossible...

They actually do something heroic.