Chloe Singles (more properly Chloe Curious or Chloe Smith , since it is her known parent's family name) is a young, loving alien-Sim hybrid living with her three roommates, friends Erin Singles and Kristen Singles, and her twin-sister, Lola Singles. She also has six half-siblings: Johnny Smith, Jill Smith, Jenny Smith, Pascal Curious, Vidcund Curious, and Lazlo Curious. Her alien father Pollination Technician 9 is married to her half-sister, Jenny Smith, who is also the daughter of Glarn Curious, Chloe's human father. Many people disagree with Chloe and Lola's twin-hood as Lola is older at the start of the game. However when you go to make a story for the Curious brothers there is a picture of Glarn having the twins and of them growing up with Glabe as their mother.
For some reason, the familial relation between the twins and the Curious siblings was left out by Maxis, thus Chloe and Lola can marry Vidcund, Pascal, Lazlo, or Jenny, their half-siblings via their father; but you can fix this problem with SimPE. On the other hand, the familial relation between the twins and the Smith children, Jill and Johnny, is evident and they recognize them as family. Since Glarn is implied to have abandoned Lola and Chloe when they were babies, it is likely that they never found out that their father remarried and had other children.