She was born Maria Eulalia Francisca de Asis Margarita Roberta Isabel Francisca de Paula Cristina Maria de la Piedad. Eulalia was born in 1864. When she grew up, Spain was violently lurching through decades of political turmoil, Cuba was a restive Spanish possession, locomotives were high tech, and Alexander Graham Bell and Elisha Gray battled over who invented the telephone. She visited the USA in 1893 to visit the Chicago World's Fair by way of Puerto Rico, Cuba, Washington DC, and New York, creating a stir wherever she went. Her USA visit was well-documented, including a run-in with Bertha Palmer, wife of hotelier Potter Palmer, a case of an irresistible force meeting an immovable object. She died in 1958 when Franco was ruling Spain, Cuba was independent but struggling under foreign businesses such as United Fruit and American organized crime, but also when a trip to the USA took just hours on a brand new Boeing 707, she could listen to radio and watch television or drive/ride in cars, and she may have looked up and seen a Sputnik overhead. Her life spanned the greatest technological and political leaps in human history.
The technological leap eased life's burdens, liberated men and especially women from drudgery, ended plagues, spanned the globe, and freed humans from the solar day; the information revolution is trifling in comparison (the 40 hour or 32 hour week are more liberating than 24/7 work made possible by instant ubiquitous communication).
The political leap moved most of the developed world from dictatorships and monarchies to constitutional monarchies and democracies that had various combinations of social and private enterprises that took care of human needs (though now, globalization may destroy the ability of some developed countries, particularly the USA, to meet even basic human needs). Once warring nation states were merging into the "European Coal and Steel Community" now expanded into the European Union that includes Spain. One indicator of political change was and is the importance of the Duke and Duchess of Galliera, a residue from the Borbone rule in Italy. Her predecessor was Luisa Fernanda who was her maternal aunt, her successor was Princess Beatrice of Saxe-Coburg and Gotha who was a granddaughter of Queen Victoria. Today the post is abolished and the future of the Spanish monarchy is uncertain.
Her Wikipedia article is here.