Question: Who is a cast member of the show featuring the Lahnstein family?

full_context: Document 1: 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 2: 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 3: Lahnstein family: The Lahnstein family is a very wealthy and aristocratic prestigious fictional family on the German soap opera "Verbotene Liebe (Forbidden Love)". The Lahnsteins have been a staple on "Verbotene Liebe" since their introduction in September 2003.
Document 4: 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 5: Hagen von Lahnstein: Hagen von Lahnstein is a fictional character on the German soap opera "Verbotene Liebe". The character has been played by Christoph Mory, after being introduced by Tom Viehöfer.
Document 6: Johannes von Lahnstein: Johannes von Lahnstein is a fictional character on the German soap opera "Verbotene Liebe (Forbidden Love)". The character was portrayed by actor Thomas Gumpert from 23 September 2003 to 9 January 2008.
Document 7: Sebastian von Lahnstein: Sebastian von Lahnstein is a fictional character from the German soap opera "Verbotene Liebe (Forbidden Love)". The character was portrayed by actor Joscha Kiefer from November 26, 2007 to October 13, 2009. The part was recast with Sebastian Schlemmer who took over the role on October 19, 2009.
Document 8: 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 9: Constantin von Lahnstein: Constantin von Lahnstein is a fictional character on German soap opera "Verbotene Liebe (Forbidden Love)" and was portrayed by actor Milan Marcus. He made his first appearance on 9 December 2004. The character was introduced as the last original member of the Lahnstein family as a troublesome teenager that grow up at his aunt's in Italy after his mother died. He has been featured in numerous storylines, including finding his biological father, his friendship to Paul Brandner, his relationships to Paul's sister Lisa and Judith Hagendorf and an affair with the former wife of his cousin, Nathalie Käppler. Marcus decided to focus on college in 2008 but stayed with the show until his last appearance on 5 January 2011.
Document 10: Helena von Lahnstein: Dr. Helena von Lahnstein is a fictional character of the German soap opera "Verbotene Liebe (Forbidden Love)". The character has been played by Renée Weibel since October 5, 2009.
Document 11: 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 12: 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 13: 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 14: 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.
Document 15: 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.
ground_truth: Valerie Niehaus
sub_queries: What show is Lahnstein family from? Answer: Verbotene Liebe
Verbotene Liebe >> cast member Answer: Valerie Niehaus