This actually explains the statement in the EDIT: fourth where one of the kids says that Lois got them all together before she died and made them promise to accept Clark's new wife. She knew she would be coming back, and paved the way for a good reception into her own family. dizzy

Quote
"Do you think your family will mind that I'm taking her place?" Lori asked.

"No." Clark pulled her into his arms. "I talked to all four of themabout this months ago, and they urged me to go for it. Lara said that Lois spoke to them privately, years back, without telling me
about it and just about ordered them to make any new wife of mine welcome."