Wendy Crewson says her character was a minor when Burnett kidnapped her and later specifies she was 14. Crewson was born in 1956, so she was about 56 in 2012. Since Burnett was shown as being in Alcatraz for her crime circa 1960, this would have made her a small child at the time, not a teenager.
Burnett is seen shooting one officer outside Helen's home, no other officer was shown. Later Hauser says Burnett killed both officers at Helen's house.