Confirmation help?!?! St. Petronilla of ___?

For my confirmation, i have to have a saint name. i chose St. Petronilla, daughter of St. Peter. For the worksheet i have to fill out, i need the full saint's name- ex. St. _______ of _______. All i have is St. Petronilla of ______. i cant find out anywhere what the second part was. please help me, what is the second part?