"In a moment of madness" huh? Yeah, i'm going to have to go ahead and call BS on that, dude! I don't care how devastated Maria was, murdering children is not a normal response, and a homicidal rage doesn't just happen one day. Maria was obviously a very disturbed woman and likely the jealous and possessive sort as well. As such, it seems very likely that Maria's behavior drove Fernando away, and Maria murdered their children out of spite. Fernando was certainly a philandering scumbag, but Maria was a psychotic, child murdering monster.