Question: Who is the godmother of the youngest child of Rainier III?

Context paragraphs:
Caroline, Princess of Hanover: Caroline, Princess of Hanover (Caroline Louise Marguerite Grimaldi; born 23 January 1957), is the eldest child of Rainier III, Prince of Monaco, and American actress Grace Kelly.  She is the elder sister of Prince Albert II and Princess Stéphanie.  Until the births of her niece and nephew Princess Gabriella and Prince Jacques of Monaco in December 2014 she had been heir presumptive to the throne of Monaco since 2005, a position which she previously held from 1957 to 1958.

Zoological Garden of Monaco: The Jardin Animalier de Monaco is located on the Esplanade Rainer III, in Monaco's Fontvieille ward, on the southern side of the Rock of Monaco.  They were established by Rainier III, Prince of Monaco in 1954.  250 animals are held in the zoo, representing some 50 species.

Prince Rainier Day: Prince Rainier Day is celebrated annually in Monaco on the anniversary of the 19 November 1949 coronation of Rainier III, Prince of Monaco.

Elisabeth-Anne de Massy: Elisabeth-Anne de Massy (Noghès) was born in Monaco on 13 January/13 July 1947 to Princess Antoinette of Monaco and her then lover Alexandre-Athenase Noghès.  She is a first cousin of the reigning Prince Albert II and niece of Rainier III.  She is the godmother of Princess Stéphanie of Monaco.  Although Elisabeth-Anne was born out of wedlock, her parents married in 1951, thus legitimizing her, and placing her in line to the throne.

Prince Pierre Foundation: The Fondation Prince Pierre was established by Prince Rainier III of Monaco in February 1966 to promote culture and the arts through the creation and the awarding of prizes.  Prince Rainier III created the foundation in tribute to his father, Pierre de Polignac a great patron of the arts.

Pierre Casiraghi: Pierre Rainier Stefano Casiraghi (born 5 September 1987) is the younger son of Caroline, Princess of Hanover, and her second husband, Stefano Casiraghi.  His maternal grandparents were Rainier III, Prince of Monaco, and American actress Grace Kelly.  Casiraghi is seventh in the line of succession to the Monegasque throne, following his twin cousins, his mother, brother Andrea, nephew Alexandre, and his niece India Casiraghi.

Charlotte Casiraghi: Charlotte Marie Pomeline Casiraghi (born 3 August 1986) is the second child of Caroline, Princess of Hanover, and Stefano Casiraghi, an Italian industrialist.  She is ninth in line to the throne of Monaco.  Her maternal grandparents were Rainier III, Prince of Monaco, and American actress Grace Kelly.  She is named after her maternal great-grandmother, Princess Charlotte, Duchess of Valentinois.

Music of Monaco: Monaco is a city and independent state located in the south of France, along the Mediterranean coast.  The country has long been under the control of the Grimaldi family, who have encouraged musical development.  Prince Rainier III introduced the Prince Rainier III Prize for Musical Composition to reward Monegasque musicians.

Princess Stéphanie of Monaco: Princess Stéphanie of Monaco, Countess of Polignac (Stéphanie Marie Elisabeth Grimaldi; born 1 February 1965) is the youngest child of Rainier III, Prince of Monaco, and American actress princess Grace of Monaco, and the sister of Albert II, Prince of Monaco, and Caroline, Princess of Hanover.  Currently 11th in the line of succession to the Monegasque throne, she has been a singer, swimwear designer and fashion model.

Rainier III, Prince of Monaco: Rainier III (born Rainier Louis Henri Maxence Bertrand Grimaldi; 31 May 1923 – 6 April 2005) ruled the Principality of Monaco for almost 56 years, making him one of the longest ruling monarchs in European history.

Supporting paragraphs: Elisabeth-Anne de Massy Princess Stéphanie of Monaco
Answer: Elisabeth-Anne de Massy