Mark 1

We read of Peter and Andrew that they were -

"...casting a net into the sea: for they were fishers.
17 And Jesus said unto them, Come ye after me, and I will make you to become fishers of men."  (Mark 1:16–17)

There is no question, as we read later, that Peter was married.  To immediately leave one's employment would be hard for the family.  Mark then relates that -

"...when they were come out of the synagogue, they entered into the house of Simon and Andrew, with James and John.
30 But Simon’s wife’s mother lay sick of a fever, and anon they tell him of her.
31 And he came and took her by the hand, and lifted her up; and immediately the fever left her, and she ministered unto them."  (Mark 1:29–31)

Mark doesn't say much about that afterwards, but in my opinion, this miracle was for Peter's wife which probably strengthened her testimony which allowed Peter to spend so much time in the Savior's service.