In the traditional Superman comics, there's no mention of him having twins. The focus is usually on his solo adventures and interactions with other superheroes.
Agatha Harkness did not eat the twins in the comics. The storylines of the comics don't include such a disturbing event. Usually, the character's actions are in line with the established lore and themes.
Agatha Harkness doesn't eat the twins in the comics. The comic storyline doesn't feature such a disturbing event. It's likely a misconception or rumor.