Wyndham Goold
Wyndham Goold( 1812-1854) was a Member of Parliament( MP) for County Limerick from 1850 to 1854.
Goold was educated at Westminster School and Trinity College, Dublin.
He was the son in law of Frederick Falkiner Goold, Archdeacon of Raphoe and brother in law of Bishop Hamilton Verschoyle
Greg Penner
Gregory B. Penner( born December 18, 1969) is an American businessman and venture capitalist.
Penner was named the chairman of Walmart on June 5, 2015.
He is the son-in- law of S. Robson Walton and the grandson- in- law of Sam Walton, the founder of Walmart.
Mathilde Seigner
Mathilde Seigner (born 17 January 1968) is a French actress.
Seigner was born in Paris, France.
She is the granddaughter of actor Louis Seigner (1903–1991).
Seigner is the sister of Emmanuelle Seigner and a niece of Françoise Seigner.
Romanos Argyros (10th century)
Romanos Argyros was a Byzantine aristocrat and son-in- law of Emperor Romanos I Lekapenos.
Charles Francis Norton
Charles Francis Norton( 1807 – 1835) was a 19th- century Member of Parliament for Guildford.
Norton was also a Captain of 52nd Light Infantry; son-in- law of Sir Colin Campbell; brother- in- law of writer Caroline Norton
Emmanuelle Seigner
Emmanuelle Seigner (born 22 June 1966) is a French actress, former fashion model, and singer.
She is known for her roles in "The Diving Bell and the Butterfly" (2007)
, "The Ninth Gate" (1999) and "Frantic" (1988).
She has been nominated for a César Award for Best Actress for "Venus in Fur" (2013), and for two César Awards for Best Supporting Actress in "Place Vendôme" (1998) and
"La Vie
En Rose" (2007).
She is married to Polish film director Roman Polanski.
Robert Vadra
Robert Vadra is an Indian businessman, entrepreneur and the husband of Priyanka Gandhi.
He is the son -in- law of Sonia Gandhi and Rajiv Gandhi, and the brother- in- law of Rahul Gandhi.
Lee Chan-hyuk
Lee Chan- hyuk( born September 12, 1996), is a South Korean singer, songwriter and producer.
He debuted as a member of the sibling duo AKMU in April 2014, under YG Entertainment.
Nick Sidi
Nick Sidi( born 22 February 1966 in Manchester, England) is an English actor.
He is the son -in- law of actress Rosalind Knight and brother- in- law of actress Susannah Elliott- Knight.
He often plays drama or comedy roles on television and frequently appears in BBC dramas.
Robert W. Levering
Robert Woodrow Levering( October 3, 1914 – August 11, 1989) was a U.S. Representative from Ohio, son-in- law of Usher L. Burdick and brother- in- law of Quentin N. Burdick.

Question: Who is the sibling-in-law of Mathilde Seigner?
Answer: Roman Polanski