Alexis Castle

Alexis Castle is the daughter of writer Richard Castle and the stepdaughter of NYPD 12th Precinct Captain Kate Beckett on Castle and also as a crossover character on How to Get Away With Murder.

Richard Castle
Richard Castle is Alexis' father and he's also working with Kate Beckett due to their dislike of Annalise Keating.

Victoria Gates
After Alexis and her friends were found by her father Richard and her grandfather who works for the CIA, Alexis befriended NYPD 12th Precinct Captain Victoria Gates. Although, Gates told Alexis' father Richard that she was too young to work for the NYPD, but that didn't stop her from going to work undercover after Gates was promoted to Deputy Chief and was reassigned to One Police Plaza.

James Johnson
Alexis is in a good relationship with James Johnson back in New York City. They hang out together as friends just like Richard Castle hanging out with Randy Johnson in Philadelphia.

Austin Perlmutter
Alexis dislikes Austin Perlmutter just like his father Sidney Perlmutter dislikes Alexis' father Richard Castle.