I put forth this theory a few months ago just to be rabidly shot down by everyone insisting it had to be a queen that usurped Cersie. Even after I searched online, found the exact text and posted it (which said nothing about it being a more beautiful QUEEN) they still shot me down so I gave up. I will laugh and laugh when we are proven right.
As far as her holding Jaime dear...well..Jaime is her power right? Someone annoys her, Jaime will take care of it (which was mentioned in a quote upstream). She's in trouble? Jaime will save her. He's not even a person to her, he's an appendage.