Who was the worst sister in Dallas?

[Willie Oleson]

And while Steven and Fallon not knowing about Adam might not make much sense logically, it does evoke a childhood spent in an atmosphere of secrets, lies and whispered conversations.

Blake also made a point, not meant to be challenged, that the "Alexis" period was a closed chapter. Even if they suspected anything then Steven would be afraid to ask and Fallon wouldn't want to upset her father.
It's not difficult to imagine that the globetrotting oil heiress would bump into an eager tabloid reporter asking her about the old family tragedy, But if she can repress the memory of shooting Roger Grimes then she can repress anything.
And I feel that these soaps never had to justify the things they never showed in the first place. The line between retcon and "previously not mentioned" is blurry.

 

[CeeCee72]

And I feel that these soaps never had to justify the things they never showed in the first place. The line between retcon and "previously not mentioned" is blurry.

Exactly. Like with Jason in Dallas - I don't feel like that was a retcon. While it seems odd that Jock never mentioned his brother, we aren't privy to every private conversation between characters. Also, there wasn't any real reason for Jock (or any other Ewing) to talk about Jason until Jamie showed up.

 

[James from London]

Correct me if I'm wrong, but we never heard of Clayton Farlow and his refineries until Sue Ellen got tangled up with Dusty, did we?

Well, just to make things even more enjoyably confusing, when Dusty first tells Sue Ellen he was raised on the Southern Cross Ranch, she replies, "I thought the Wayne family owned that?" He explains that they do, and that Farlow is his mother's name (which of course it was, but not necessarily in the way he meant).

Clayton first comes into JR's orbit when Sue Ellen takes John Ross to live at the Southern Cross, but I can't remember if JR recognises his name when Harry McSween mentions it. Interestingly, it isn't until JR confronts Sue Ellen and the Farlows at the Southern Cross that he realises the man she left him for is the same rodeo rider she was flirting with at Southfork two years earlier, as he has no idea she and Dusty have been seeing each other in the interim (or that Dusty died and came back to life, come to that).

 

[Willie Oleson]

Hmm, yeah....I see it now: those traditional Third Soap Families.
The First Family lived in the characteristic mansion (Ewings, Carringtons, Channings) and they were feuding with the Second Family (Barneses, Colbys, Giobertis) and every now and then they got involved with the Third Family (The Claytons Farlowes, Blaisdels - replaced by Dexters - and the Agrettis).
It's less clear in Knots but considering the soap as a whole I'd say the Ewings, the MacKenzies, the Sumners.
There were also Fourth Families, kinda bargain bin quality like the McKays and the Fallmonts - so we all agree that Kristin was not the worst sister? great! - but the Rylands were very good, yeah.

 

[Laurie Marr]

Let’s also bear in mind that there are also competing narratives in many off screen families about what happened when and why and who did what to whom and for what reason. I know of several from my own family that would put the oversights and dodgy timelines of the Ewings and the Carringtons to shame.