Carol, I've said this in the On the Other Hand FDK thread as well.
Do you know how much these stories remind me of your "Sister Switch"?

Of course, they are not exactly the same (the colonial time is certainly a difference), but similar enough.

Spoiler Space
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Let's see.
(1)Lois/Leah is forced to marry Clark/Cal because of circumstances that she can't control.

(2)Cal/Clark chooses to marry Lois/Leah because of extreme circumstances.

(3)Lois/Leah falls in love with Clark/Cal before he does.

(4)Clark/Cal is still in love with someone else while he is married. (Or at least believes he is).

(4)They have a sexual exprience (or almost exprience) where Clark/Cal calls Lois/Leah by the name of the person he is love with.

(5)Lois/Leah gets pregnaut with Clark/Cal's baby while he is still in love with someone else.

(6)They fall in love for real.


And of course, now we have the "twist" that was at the beginning of "Sister Switch."
Lois and Clark know they're married, they WANT to be married, but they wake up and he's married to someone else.

So who is responsible?

Mindy? - She was mentioned before, but's unlikely that she could pull off something like this.

Lex? - They don't know him yet, and he certainly doesn't know their connection to the superheroes.

Tempus - Most likely.

H. G. Wells - Possible.

And I'm remembering a "FDK related thread" where Lois finds out her parents are still together, but she isn't married to Clark.
Well, her parents never divorced in this story, but Ellen and Lucy DID die.
Lois probably wants to find out how she can keep her mother and Lucy alive, while still staying married to Clark.

Have I mentioned how much I love time travel stories?