Question: who plays barney's sister on how i met your mother
Answer: Barney has three half - siblings : James ( played by Wayne Brady ) , from his mother 's side , a gay African American who is married to a man , with whom he has an adopted son and daughter ( as revealed in the season seven episode `` The Rebound Girl '' ) ; Carly ( played by Ashley Benson ) , a university student from his father 's side with whom Ted has a one - night stand in `` Ring Up ! '' , and Jerome Jr .