Lois should realize that her accepting the new Clark is inherently different than Martha and Jonatha accepting him. Having multiple children is acceptable, having multiple significant others is generally frowned upon.
True, remarriage after the death of a spouse, and finding a new boyfriend/fiance are totally acceptable in most cultures (there are esceptions), but few people accept such moving on to happen after only a week. Have reservations about loving new Clark at this point is totally acceptable.
I know at some level I should think the same things about Clark, but since his Lois died over a year ago in his lived time experience, I figure he is not in the same greeving phase.