Manuela María Maximiliano de la Ossa Escobar was born on 2 March 1855 in Sahagún, Chinú Province, Bolívar State (when it was part of the Republic of New Granada, now Córdoba Department, Colombia) to Manuela Escobar Arce and Jose Francisco de la Ossa Molina.

[1][Notes 1] Her father was the Chief Justice of the Supreme Court for the Isthmus Department of Colombia[5][6] and her maternal grandfather and his brothers were signers of the Declaration of Independence of Panama from the Spanish Empire.

[7] Her siblings included: Jerónimo (1847–1907), who wrote the National anthem of Panama;[6][8] Ramona (1849-prior to 1919)[9][Notes 2], who married the legislator Manuel C. Cervera;[12][13] Emilia (1850–1938), mother of Edwin Lefèvre, who was a women's rights advocate and later a writer;[6][14] José Francisco Ramón (1851–1852);[15][16] José Francisco (1856–1956), who served as Mayor of the Isthmus Department and later a Superior Court Judge;[17] Ricardo (1860–1907), who owned a Peruvian business;[18][19] and Manuela Augusta (1864–?

[21][11] De la Ossa was raised in an era of rigid custom, where upper-class women were kept separate from society and trained in the arts of music and needlework, to prepare them for marriage and the domestic sphere.

[29] A third, smaller flag was made of the fabric remnants by María Emilia, Angélica's daughter[29][30] and the women were assisted by de la Ossa's domestic helper, Águeda.

[28] On 3 November 1903, word reached separatists in Panama City, that General Juan B. Tobar, was landing with the cruiser Cartagena and merchant ship Alexander Bixio from Colombia to the coastline near Colón.

Fearing that if they were caught they would be executed, Amador, along with José Agustín Arango, Federico Boyd, and Manuel Espinosa Batista met to discuss the situation.

[27] When Amador went to speak with Prescott, de la Ossa left and met with Arango and Espinosa, husband of her cousin, to reassure them that the plans were proceeding and convince them to remain steadfast to the cause.

[29] The third flag, which was retained by de la Ossa was later given as a gift to President Theodore Roosevelt and is believed to have been later donated to the Library of Congress.