Kate is a potential love interest for Niko, and is the youngest member of the McReary household. According to Packie, she witnessed several bloody fights between her brothers at a young age. Supposedly, seeing Gerry beating Francis was a traumatic moment in her childhood.
Kate lives by traditional values (according to Packie, 'she won't put out'. Kate only views Niko as a friend, and not as a love interest. You can ask to come inside, though she will always reject the idea.
Kate likes clothes from the Russian shop. You do not need to increase her Like %.