Speaking for myself....
I am betting that Clark would tell Lois earlier, before they get married and this is my reasons.
From canon, (I think) Clark wanted to wait for the special someone that he could share the rest of his life with. That's why he was a virgin in the series. He knew that he was 'special' and that he couldn't commit to another person until he knew that that person could accept all that he was.
When he created Superman, that really complicated things. Lois went ga-ga over the creation, so Clark knew that she could accept the 'special' aspects of his life, however, she was totally ignoring his 'normal' side, which had to hurt. So, in his mind, his 'normal' side had to win her over.
Lois meeting Clark before he created Superman wouldn't have that issue. Much like Nan's Second Choice, Clark couldn't help but eventually reveal himself to her. She would eventually do 'something' that Clark would have to rescue her from.
As for the kid. In my opinion, again, if they have a kid, it will probably be super in some aspect, if not all aspect(darn those dominant K genes
) and at some point they would have to reveal to the child his nature. At that point, he would have to also know that CK=S.
Now, I think it would be an interesting twist if this didn't happen until after the 'series' started. The child would be turning 10, just around the time that Clark had exhibited his powers. Maybe up until this point, LnC thought that they had a normal kid, and then something happens that is impossible for a 10 year old to do.
Trust me, having three under the age of 8, there is nooooo waaayyy that I would tell them I had special abilities until I absolutely had to.
Now, of course, early on, when they were like under the age of 1 and a half, there might be some flying going on and some other things, but that would disappear fast the first time they say "My daddy can fly!"
James
