About the name Guillermina
Guillermina belongs to the Spanish tradition. Its roots are documented, even though its precise meaning is not recorded in the standard references — an honest gap we prefer to a confident guess.
In the United States, Guillermina first appears in Social Security records in 1918. It climbed to its best-ever rank of #1806 in 1966, and in 2024 6 babies received the name — 1,924 in total since 1880. Those are the official counts, not estimates.