Beatrix is the original Latin form of Beatrice — from beatus, meaning "blessed" or "happy." Beatrix Potter (1866-1943) is the most famous English bearer; three queens of the Netherlands have also borne the name.
Beatrix is rising rapidly in the U.S. as part of the broader return of Latin classics. The character Beatrix Kiddo ("The Bride") in Tarantino's Kill Bill kept it modern. Today Beatrix sits in the U.S. top 600 and is climbing fast.
Beatrix reduces to three — the number of blessed cheer.