question: Who is the sister of the man who was lovers with a local school teacher?
context: Melanie Daniels, a young socialite, meets criminal defense attorney Mitch Brenner in a San Francisco pet shop. Mitch wants to purchase a pair of lovebirds for his sister's eleventh birthday, but the shop has none. He recognizes Melanie from a court appearance, but she does not know him; he plays a prank by pretending to mistake her for a saleswoman. Melanie is infuriated by the prank—but finds herself romantically intrigued by Mitch.
  Melanie purchases a pair of lovebirds and drives to Mitch's weekend address in Bodega Bay to deliver them. Wanting to surprise him, she rents a motorboat so she can approach the Brenner house from the bay instead of the road. She sneaks the birds inside the house and heads back across the bay. Mitch discovers the birds, spots Melanie's boat during her retreat, and drives around the bay to meet her. Melanie is attacked and injured by a seagull near shore on the town side. Mitch treats her abrasion and invites her to dinner; she hesitantly agrees.
  Melanie gets to know Mitch, his domineering mother Lydia, and his younger sister Cathy. She also befriends local school teacher Annie Hayworth, Mitch's ex-lover. While spending the night at Annie's house, she and Annie are startled by a loud thud: a gull kills itself by flying into the front door. At Cathy's birthday party the next day, the guests are attacked by seagulls. The following evening, sparrows invade the Brenner home through the chimney.
answers.text: Cathy