Trump co-owns the Miss Universe, Miss USA and Miss Teen USA pageants with NBC Universal.
Meriwether was the reigning Miss Maryland USA. She was named first runner-up at the 2012 Miss USA Pageant.
Meriwether, 27, was born in South Africa when her parents were there as volunteers.
"Inspired by the eight years of pro bono medical and community work her father and mother did in Southern Africa in the 1980s, Nana co-founded a 501(c)(3)international nonprofit organization, The Meriwether Foundation," according to her pageant biography. "Seeking to support and sustain AIDS/HIV orphanages, schools, rural clinics, and community and agricultural projects, The Meriwether Foundation has grown to operate in five countries in Southern Africa (South Africa, Zimbabwe, Zambia, Malawi and Mozambique). Nana is co-founder, director and chairman of The Meriwether Foundation and has spent up to three months living in Southern Africa cultivating the many Meriwether Foundation projects present in several remote villages."