Question: When Vladimir Kashpur portrayed Baba Yaga she was one of how many sisters?

Context paragraphs:
Georgy Millyar: Georgy Frantsevich Millyar, sometimes spelled Milliar (Russian: Георгий Францевич Милляр ) (7 November 1903 in Moscow – 4 June 1993 in Moscow), was a Soviet/Russian actor, best known for playing evil spirits in Soviet fairy tale films, including the witch Baba Yaga in films such as "Vasilisa the Beautiful", "Jack Frost", and "Fire, Water, and Brass Pipes".

The Golden Horns: The Golden Horns (Russian: Золотые рога), also known in English as Baba Yaga, is a 1973 Soviet adaptation of a Russian fairy tale.

Isabelle De Funès: Isabelle Christine Inès Léonore Girard (born July 27, 1944), better known by the name Isabelle De Funès, is a French actress, singer, model and photographer.  She is best known for her portrayal of Guido Crepax's comic book character Valentina in the erotic thriller, "Baba Yaga" (1973).

Baba Yaga (film): Baba Yaga is a 1973 horror film directed by Corrado Farina and based on the Guido Crepax's "Valentina" comic series.  The film stars Carroll Baker, Isabelle De Funès and George Eastman.  It is about a Milanese photographer Valentina Rosselli who meets a middle-aged seductress who calls herself "Baba Yaga".  She shows an ostensible sexual interest in Valentina and gives her a doll dressed in leather fetish wear.  It is soon revealed that Baba Yaga has started to control Valentina through the doll.

The Dancing Hut of Baba Yaga: The Dancing Hut of Baba Yaga is an adventure module for the 2nd edition of the "Advanced Dungeons & Dragons" fantasy role-playing game.

Guido Crepax: Guido Crepas (15 July 1933 in Milan – 31 July 2003 in Milan), better known by his "nom de plume" Guido Crepax, was an Italian comics artist.  He is most famous for his character "Valentina", created in 1965 and very representative of the spirit of the 1960s.  The "Valentina" series of books and strips became noted for Crepax's sophisticated drawing, and for the psychedelic, dreamlike storylines, generally involving a strong dose of erotism.  A film based on his work called "Baba Yaga", featuring the character Valentina, was made in 1973.

Baba Yaga: In Slavic folklore, Baba Yaga (Russian: Баба-яга, Polish: Baba Jaga) is a supernatural being (or one of a trio of sisters of the same name) who appears as a deformed and/or ferocious-looking witch.  Baba Yaga flies around in a mortar, wields a pestle, and dwells deep in the forest in a hut usually described as standing on chicken legs (or sometimes a single chicken leg).  Baba Yaga may help or hinder those that encounter or seek her out.  She sometimes plays a maternal role, and also has associations with forest wildlife.  According to Vladimir Propp's folktale morphology, Baba Yaga commonly appears as either a donor or villain, or may be altogether ambiguous.

Old Witch Boneyleg: Old Witch Boneyleg is a 1978 anthology of 13 fairy tales from around the world that have been collected and retold by Ruth Manning-Sanders.  It is one in a long series of such anthologies by Manning-Sanders.  This is a companion volume to "The Haunted Castle".  The book's title story is a Baba Yaga tale, although it does not mention the witch by name.

Jan Cornall: Jan Cornall (born 17 August 1950) is an Australian singer, comedian and writer.  Known for her contributions to queer music through the group Baba Yaga during the 1970s and the hit musical "Failing in Love Again" (1979), Jan Cornall was a leader in the women’s comedy and cabaret resurgence of the early 1980s.  She has contributed to Australian community theater, addressing issues facing regional and rural women, and had a long involvement in forging cross cultural links with Indonesian and Australian writers and artists.

Vladimir Kashpur: Vladimir Terentyevich Kashpur (Russian: Владимир Терентьевич Кашпур ) (October 26, 1926 – October 17, 2009) was a Russian and Soviet actor.  A native of Severka, Altai Krai, Kashpur appeared in "Ballad of a Soldier" and about 115 other films, with roles ranging from Vladimir Lenin to Baba Yaga.  Kashpur was also active in the Moscow Art Theatre.

Supporting paragraphs: Vladimir Kashpur Baba Yaga
Answer: trio of sisters