Here is some information I have found on the Montalvo name.Hope it is of some use.
Maureen Montalvo Pinzon
The surname Montalvo, or Montalbo, is very extensive throughout Spain.Whether or not it has a common origin is not known.Branches of the family have been identified prior to 1500 in Soria, Palencia, Valladolid, Avila, and Madrid, plus in Portugal and Italy.
Family histories have been identified for the Montalvo in Cuba and Peru.In the United States, Montalvo is the 189th most popular surname among modern Hispanic families.
Lorenzo Montalvo y Montalvo, a son of Pedro Lorenzo Montalvo y Montalvo and Teresa Montalvo y Avellaneda, was born a Medina del Campo in Valladolid about 1710.His genealogy can be traced nine generations beyond him.He arrived in Havana, Cuba in 1734 as the first of his family on that island.His posterity is very extensive there and in the United States.He had eleven children by his first wife, Mariana Brun~a de Ve'rtiz.
In Puerto Rico, Juan Montalvo Can~ete, son of Francisco Montalvo, and his wife Mari'a, a native of Torrija, Teruel, Spain, was attached to the Batallo'n Provisional de Puerto Rico as a private in 1898.He returned to Spain that year.
In early California, Bernardo Montalba was at Los Angeles in 1846.There were no Montalvos in Arizona, Colorado, New Mexico, Colorado, Louisiana, or Florida as far as can be determined.
In Texas, the family was fairly extensive.Andre's Montalbo, a Spaniard, a farmer, native of Ri'o Grande, age 26, was married and living at San Francisco de la Espada mission in 1793.He had two sons. Also there was Juana Montalbo, wife of Este'van Galindo.They were Indians.At Sen~or San Jose' mission, Felipe Montalvo, a mulatto from Grun~idora, Mexico, age 33, lived with his wife and one son.At San Fernando de Austria in 1797, Miguel Montalbo, a Spaniard, age 52, and his wife Juana Herna'ndez, had two daughter.Living next to them, Mari'a Thomasa Montalbo, age 22, possibly a daughter, and her husband Alejandro Mansolo, had two small sons.At La Bahi'a in 1804, Domingo Montalvo and his wife were stationed at the presidio.
The Montalvo family identified in Aguadilla, Puerto Rico are as follows:Ana, died in Aguadilla June 26, 1989, born August 15, 1924; Enriqueta, born September 23, 1901, died in Aguadilla in February of 1978; Fidencia, born April 3, 1908, died in Aguadilla in February of 1988; Mari'a, born October 22, 1901, died in Aguadilla in September of 1974; Victoria, born May 14, 1989, died in Aguadilla in December of 1972; Miguel, born October 25, 1915, died in Aguadilla in June of 1977.