Last Name Spelling Help Please

Hi everyone, any help would be appreciated. I have over 20 records from my 5th Great Grandmother Maria Paulina. Her last name is spelled so many different ways by the priest and scribers. Here are some examples( Sartica, Esatiga, Zartiga, Sastiga, Exartiga, Estatiga, Saxtiga, Exatiga and some gave up and just wrote Sanchez)Does anyone know what the correct spelling would be. Any help would be appreciated.
BTW
Maria Paulina was married to Manuel Salvador Roxas.I havent found their marriage record yet but they might have originated from Jalisco and definately settled in Amatlan de Jora, Nayarit.

Thanks
Ruben Rojas Delgado