Jesus says to the woman, "you have had five husbands; and he whom you now have is not your husband" (4:18). Does John say what happened to her husbands, or why Jesus spoke of them?

Here is what John tells, in order. "Jesus said to her, “Go, call your husband, and come here.”" (4:16). "The woman answered, “I have no husband.”" (4:17). Jesus answers, "You said well, ‘I have no husband,’" (4:17), "for you have had five husbands; and he whom you now have is not your husband. This you have said truly" (4:18). She says, "Sir, I perceive that you are a prophet" (4:19). John doesn't say how any of her marriages ended, or who the man she now has is, or why Jesus said, "Go, call your husband" (4:16). He tells what she said afterward to the people of the city: "Come, see a man who told me everything that I have done" (4:29), and that "many of the Samaritans believed in him because of the word of the woman" (4:39). These notes say no more about her life than these verses do, and apply nothing in them to anyone's marriage.