She runs the Spear Fisher shop down on the beach. At the beginning of the game, she'll give you a free fishing pole if you walk to the end of the boat dock; you don't need to talk to her to get it, though.
It's possible to reunite Sabrina and Neuman during the first year of the game. If you speak to Neumann in church he'll mention that he once angered Sabrina, but won't get into detail. Go see Sabrina in her bedroom and she'll mention that they used to be married. Neumann will tell you if you bring this up in the pub why Sabrina divorced him, and if you ask Sabrina about the story she'll mention that she hid the Stroller Chalice that came between them somewhere in Kasmir Ruins.
You can find the Stroller Chalice in the far right corner in the back of the ruins. If you bring it back to Sabrina the two will get remarried, though they will continue to live in separate homes, so you'll have to give it to Neumann in order for their second marriage to take place; it can only be viewed before you get married, though.