Peter was the only one the Bible mentioned was actually married all the other apostles were assumed to most likely be married but it’s mentioned that Peter actually was married
A fever wasn’t just something curable and simple back then it was a serious disease
Jesus healing peters mother in law was like a gift to peters wife and of course his mother in law
Because Jesus knew he would be taking Peter with him and they would be gone for a long time so he healed his mother in law from almost dying so that peters wife would have someone as Peter served the lord and followed Jesus through his ministry
Jesus could have easily told Peter no and said we have other people to tend to and heal but he didn’t because he knew his plans for Peter he knew he would have to leave his wife and family and it would have been even harder on his wife if her mother had passed away now in 1 Corinthians chapter 9 verse 5 it says “Don’t we have the right to bring a believing wife with us as the other apostles and the Lord’s brothers do, and as Peter does?”
This scripture indicated that many of the apostles was married as well as some of them including Peter brought along their wives as they traveled
I always believe that every time happens for a reason I believe that if jesus didn’t heal peters mother in law and she died then peters wife wouldn’t be stable enough to go with Peter when it was her time and due to that I believe Peter wouldn’t have done what he was called to do