Question: Who is the mother of the director of film Sea Sorrow?

Knowledge 1: Sea Sorrow
Sea Sorrow is a 2017 British documentary film about child refugees in the European migrant crisis, directed by Vanessa Redgrave.It was shown in the Special Screenings section at the 2017 Cannes Film Festival. [SEP] Knowledge 2: Vanessa Redgrave
Vanessa Redgrave (born 30 January 1937) is an English actress of stage, screen, and television, and a political activist.She is a 2003 American Theatre Hall of Fame inductee, and received the 2010 BAFTA Fellowship.Redgrave rose to prominence in 1961 playing Rosalind in the Shakespeare comedy "As You Like It" with the Royal Shakespeare Company and has since starred in more than 35 productions in London's West End and on Broadway, winning the 1984 Olivier Award for Best Actress in a Revival for "The Aspern Papers", and the 2003 Tony Award for Best Actress in a Play for the revival of "Long Day's Journey into Night".She also received Tony nominations for "The Year of Magical Thinking" and "Driving Miss Daisy".On screen she has starred in scores of films and is a six-time Oscar nominee, winning the Academy Award for Best Supporting Actress for the title role in the film "Julia" (1977).Her other nominations were for  (1966), "Isadora" (1968), "Mary, Queen of Scots" (1971),"The Bostonians" (1984), and "Howards End" (1992).Among her other films are "A Man for All Seasons" (1966), "Blowup" (1966), "Camelot" (1967),"The Devils" (1971), "Murder on the Orient Express" (1974), "Prick Up Your Ears" (1987),  (1996),"Atonement" (2007), "Coriolanus" (2011), and "The Butler" (2013).Redgrave was proclaimed by Arthur Miller and Tennessee Williams as "the greatest living actress of our times", and has won the Oscar, Emmy, Tony, BAFTA, Olivier, Cannes, Golden Globe, and the Screen Actors Guild awards.A member of the Redgrave family of actors, she is the daughter of Sir Michael Redgrave and Lady Redgrave (the actress Rachel Kempson), the sister of Lynn Redgrave and Corin Redgrave, the mother of actressesJoely Richardson and Natasha Richardson, the aunt of British actress Jemma Redgrave, the mother-in-law of actor Liam Neeson, and the grandmother of Daisy Bevan, Micheál and Daniel Neeson.
Knowledge 1: Sea Sorrow
Sea Sorrow is a 2017 British documentary film about child refugees in the European migrant crisis, directed by Vanessa Redgrave.It was shown in the Special Screenings section at the 2017 Cannes Film Festival. [SEP] Knowledge 2: Dana Blankstein
Dana Blankstein- Cohen( born March 3, 1981) is the director of the Israeli Academy of Film and Television.She is a film director, and an Israeli culture entrepreneur.
Knowledge 1: Trinidad Tecson
Trinidad Perez Tecson (November 18, 1848 – January 28, 1928), known as the "Mother of Biak-na-Bato" and "Mother of Mercy", fought to gain Philippines independence.She was given the title "Mother of Biak-na-Bato" by Gen. Emilio Aguinaldo.She was also cited as the "Mother of the Philippine National Red Cross" for her service to her fellow Katipuneros. [SEP] Knowledge 2: Susan B. Nelson
Susan B. Nelson( April 13, 1927 – May 4, 2003) was an American environmental activist who is best known as the mother of the Santa Monica Mountains National Recreation Area.

Answer: Rachel Kempson