Petronilla Look up Petronilla at
also Petronella, fem. proper name, a feminine diminutive of Latin Petronius. Also "the name of a saint much-invoked against fevers and regarded as a daughter of St. Peter. The name was accordingly regarded to be a derivative of Peter and became one of the most popular of girls' names, the vernacular Parnell being still used as a proper name as late as the 18th century in Cornwall" [Reaney].