May 18. On this date in 1941, Yvonne Liegois Cuellar, a French woman married to Arturo Cuellar Echazu, a Bolivian army officer, became a Bahá’í in Bolivia. Although Marina del Prado was the first Bolivian to become a Bahá’í, on February 2, 1941, she did not remain active, so Yvonne Cuellar is recognized as the first Bahá’í in Bolivia. Shoghi Effendi called her the "Mother of Bolivia". Arturo Cuellar would later become a Bahá’í in 1946 through his wife's efforts.

May 18. On this date in 1941, Yvonne Liegois Cuellar, a French woman married to Arturo Cuellar Echazu, a Bolivian army officer, became a Bahá’í in Bolivia. Although Marina del Prado was the first Bolivian to become a Bahá’í, on February 2, 1941, she did not remain active, so Yvonne Cuellar is recognized as the first Bahá’í in Bolivia. Shoghi Effendi called her the "Mother of Bolivia". Arturo Cuellar would later become a Bahá’í in 1946 through his wife's efforts.

Born in France on March 11, 1896, Yvonne Cuellar and her husband, Arturo Cuellar, lived in La Paz, Bolivia, in the 1940s where they had an American boarder, Eleanor Adler, who was first Baha'i pioneer to Bolivia. Both she and her husband became Baha'is and helped establish the first Baha'i community of La Paz. In 1953, the Cuellars moved to the United States but returned to Bolivia in 1956 at the request of the National Spiritual Assembly of that country.

 In 1958 she traveled to France to help establish the inaugural National Spiritual Assembly, which was dissolved two years later through reports of Hand of the Cause Abu'l-Qásim Faizi by the authority of the Custodians due to a majority of the Assembly's acceptance of Charles Mason Remey's claim to being the second Guardian of the Bahá’í Faith subsequent to the death of Shoghi Effendi.
 
In 1968 the Cuellars once again moved to the United States. Yvonne Cullear died in Littleton, Colorado in December 1983.