Question: Who is a cast member from the soap opera featuring a character named Viktoria Wolf?

full_context: Document 1: Dana Wolf: Dana Wolf is a fictional character of the German soap opera "Verbotene Liebe (Forbidden Love)". She has been portrayed by Diane Willems from 27 January 2011 to 10 September 2014.
Document 2: Katja Brandner: Katja Brandner is a fictional character on German daytime soap opera "Verbotene Liebe" ("Forbidden Love"). The character was portrayed by actress Diana Frank from January 15, 2008 to January 5, 2009.
Document 3: Clarissa von Anstetten: Clarissa von Anstetten (née Prozeski and formerly Kaufmann) is a fictional character on German soap opera "Verbotene Liebe (Forbidden Love)". The character is played by actress Isa Jank from the show's debut on 2 January 1995 to 5 September 2001 and again since 21 June 2011. She left the show again on 20 March 2013.
Document 4: Kim Wolf: Kimberly "Kim" von Lahnstein (adopted Wolf, married Sanchez) is a fictional character of the German soap opera "Verbotene Liebe (Forbidden Love)". Lisa Tomaschewsky introduced the role on April 13, 2011, but was eventually recast with actress Nicole Mieth, who took over the part on May 10, 2011.
Document 5: Sarah von Lahnstein: Sarah von Lahnstein (née Käppler, formerly Hofmann) is a fictional character on German soap opera "Verbotene Liebe (Forbidden Love)". The character was portrayed by actress Sina-Valeska Jung from 11 July 2006 to 5 May 2009.
Document 6: Leonie Richter: Leonie Richter is a fictional character on the German soap opera "Verbotene Liebe (Forbidden Love)". The character is portrayed by Stefanie Bock, who debuted in the role on 9 August 2011.
Document 7: Viktoria Wolf: Viktoria Wolf is a fictional character of the German soap opera "Verbotene Liebe (Forbidden Love)". She has been portrayed by Patricia Schäfer from April 8, 2011, to October 7, 2013. The character died in 2013.
Document 8: Jana von Lahnstein: Jana von Lahnstein ("née" Brandner) is a fictional character in the German soap opera "Verbotene Liebe" ("Forbidden Love"). The character was played by the actress Friederike Sipp from 1 October 2002 to 21 March 2005. The character was recast with Vanessa Jung, who played the role from 23 March 2005 to 20 February 2008.
Document 9: Jan Brandner: Jan Brandner is a fictional character on German soap opera "Verbotene Liebe (Forbidden Love)". The character was played from the show's debut on January 2, 1995 to August 27, 1997 by actor Andreas Brucker. In March 2011, the role was surprisingly recast with actor Hubertus Grimm; reinstating the Brandner family and the original story of the show. Grimm debuted in the role on June 23, 2011. The role was reactivated on short-term for a special of the show on the Spanish island Mallorca. The character made his last appearance on January 18, 2012.
Document 10: Lydia Brandner: Lydia Brandner (divorced von Lahnstein) is a fictional character from the German soap opera "Verbotene Liebe" (Forbidden Love). The role was originated by actress Theresa Underberg on 16 January 2008. Theresa announced on 21 December 2010 that she will leave the show in early 2011. She made her last appearance on 29 March 2011.
Document 11: Timo Mendes: Timo Mendes is a fictional character from the German soap opera "Verbotene Liebe (Forbidden Love)". Remo Schulze debuted in the role on 23 June 2011. Timo is the son of Julia von Anstetten and her first husband Tim Sander.
Document 12: Judith Hagendorf: Judith Hagendorf is a fictional character on the German soap opera "Verbotene Liebe (Forbidden Love)" portrayed by actress Katrin Heß from February 18, 2008 to September 15, 2009, when the character was surprisingly written out without any conformation from the production.
Document 13: Maria di Balbi: Maria di Balbi is a fictional character on the German soap opera "Verbotene Liebe (Forbidden Love)" portrayed by actress Simone Ritscher since 21 January 2009. The character was also known by the alias Maria Galdi and the identity of her late sister Francesca von Lahnstein. She left the series on 7 January 2011. Two months later, on 17 March 2011, the character was killed off off-screen, to the anger of many fans.
Document 14: Julia Mendes: Julia Mendes (born Prozeski, adopted von Anstetten and formerly Sander) is a fictional character from the German soap opera "Verbotene Liebe (Forbidden Love)", played by Valerie Niehaus. She is introduced in the series' premiere on January 2, 1995. She departed from the series in July 1997, when Niehaus decided to pursue other roles. The role was surprisingly recast with well-known actress Nina Bott in 2011; reinstating the Brandner family and the original story of the show. Bott appeared for the first time on-screen on June 23, 2011. She eventually finished shooting her story arc in October 2011 and last appeared on January 18, 2012. The character is known as the first protagonist of the show and her main story focuses around the incestuous love to her twin-brother Jan Brandner.
Document 15: Nathalie Brandner: Nathalie Brandner (née Käppler, formerly von Lahnstein) is a fictional character from the German soap opera "Verbotene Liebe (Forbidden Love)". The character is portrayed by actress Jenny Winkler. She first appeared on 12 November 2004 and had her final appearance on 14 December 2010.
ground_truth: Valerie Niehaus
sub_queries: Viktoria Wolf >> present in work Answer: Verbotene Liebe
Verbotene Liebe >> cast member Answer: Valerie Niehaus