Family Historian User Group

I have a man on a distant branch of my tree who was married three times. He had two daughters by one of those marriages, but I do not know which.

Is there a way to unlink the daughters from a mother only, rather than both parents? Otherwise it seems my only options are (a) hazard a guess as to which wife is the actual mother, or (b) create a 4th family group. Both of these are undesirable - My guess could be wrong, and a 4th family group would suggest an additional unknown spouse/partner.

Unfortunately, Children are linked to Parent Family records NOT Individual records, so your options are (a) or (b) or (c) link the daughters to both possible Parent records, with all the usual Notes.

There are times when the "least worst" option is the only one that works.

I would agree that guessing which wife is the mother is a seriously bad idea. No matter how much you insert caveats for the reader, someone sooner or later will miss the caveats. Murphy's Law probably indicates it'll be you!

To me, the 4th family group suggests an unknown partner, and that is very different from an unknown additional partner. That's the way I'd do it.

You could try telling yourself that until you resolve who the mother is, then there is an outside chance that the mother genuinely is an additional person. Not because I think it's likely but because it might salve your conscience!

What I actually do is create a 4th family group with a genuine individual person in there (as distinct from an empty "mother") and the name of this extra person is "Unknown which /Smith/" (or whatever the husband's name is). Now I guarantee that there are people who've read that and gone thermonuclear critical at my creating a non-existent person. You may feel that yourself. But while I'm normally quite pedantic and dislike concocted values (especially members of the "Unk" family, who were born at their family seat of "Unk"), sometimes the least worst option with the visible reminder is the, well, least worst option.

I found a posting on FHUG some while ago with a link to "Roger's Research Recommendations" from Roger Firth http://www.firthworks.com/genealogy/RRR/index.html No 9 is the one that will interest you. Similar to what Adrian was suggesting but perhaps slightly better wording.
He creates a spouse and uses the forenames "Not Yet Identified //" there are other similar suggestions for differing scenarios. Also if i do not know the spouses maiden name I use the marriage name in square brackets [ ] also a recommendation from FHUG, Jane I believe.