Hey Ivan,
I'm also an Alvira. I wouldn't worry about the family name going away, my brothers and I have 5 boys between the 3 of us. Unfortunately I don't know to much about the family name other than it originated in a small town/village in Spain which I got from some genealogy service a long time ago.
I'm trying to make other connections to our family name, my dad knows very little about the Alvira's side. I've listed the only other Alvira's that I know for a fact are related, so let me know if any sound familiar. Thanks and stay safe out there.
Jaime Alvira
Great Grandfather Feliciano Alvira Y Rivera (Juana Rivera Alvira sister???)
Great Uncle (GREAT GRANDFather Brother) Nemensio Alvira Y Rivera
Great GrandMother Felipa Perez Y Perez DE Alvira
Great Uncle (GREAT GRANDMOTHERS Brother) Fransisco Peres Y Peres
Grand Father Maximo Alvira Perez BORN 11/10/13
Ms. Guadalupe ALVIRA PÉREZ 1907 Married to Haddock
Raphael
Armando
Mr. Ignacio ALVIRA PÉREZ 1909
Aida
Ms. Lucia ALVIRA PÉREZ 1910
Gladys
Mr. Manuel ALVIRA PÉREZ 1912
Mr. Máximo ALVIRA PÉREZ 1913