It stands to reason that your direct-line relative will be married a justice of the peace or another warm body able to certify marriages in close proximity to the bridal couple at the time of the event.
In these cases the genealogical clues that can be ascertained from the officiant are minimal.
Determine who married all the ancestral siblings. If the family was remotely religious (and potentially listed in church records), there’s a good chance at least one of the family members took the time to have a religious ceremony. In terms of it being a clue it doesn’t matter much if it your ancestor of interest or their sibling.
Unless the church member was the in-law. But then you’ll have to research to know that.
Which is the point.