St. Matthew recorded in the Gospel, “Jesus entered Peter’s house and found Peter’s mother-in-law in bed with a fever. He took her by the hand and the fever left her" (Mt 8:14-15). Note that the passage does not mention St. Peter’s wife, but only his mother-in-law. The Gospels, however, make no mention of St. Peter’s wife, living or nonliving. Therefore, St. Peter’s wife must have died before Jesus called him to be an apostle.
For full disclosure, Clement of Alexandria (Stromata, III) (c. 202), said St. Peter was married, had children and witnessed his wife’s martyrdom in Rome. These terse points were recorded, citing Clement, in St. Eusebuis’ The History of the Church. Given the silence of other church fathers about St. Peter’s wife and children (who would have had some prominence in the history of the early church), and the lack of any archaeological evidence of ancient Rome, which holds the burial sites of St. Peter and so many other early martyrs, one would conclude St. Peter’s wife died before he had been called as an apostle.