The way I see it you have two options, and it depends on how far you want to chase the other husbands.
If you want to trace the other husbands back a couple of generations before the marriage, add each husband to the wife with appropriated data. As you find family for the other husbands, you can add it like any other person in your tree.
If you only want to note the husbands and the fact that the wife was married to them, I would place the information in the person note for the wife.
In my research, for those side branches in the family, I add the census and similar data for the person's family in the notes . Recently I learned that two from those side branches were brother and sister. Having already collected some on the information in the notes, it was easy to add the appropriate entries to show the family connections.