No...Cersei only has ONE younger brother...Jamie is her twin, so they are the same age give or take a few minutes. And considering that she's the only thing in the world he actually cares about, even proclaiming an eagerness to kill everyone else until they are the only ones left in the world, I doubt he'll be the one strangling her.
Tyrion on the other hand has every reason to kill the heartless bitch. And as a side note, Tyrion is the only Lanister I actually like. I've liked his character from the very beginning....but at least Jamie seems to have grown and evolved as a person during his time with Briane of Tarth. Like he got to see what honor actually looks like....and it happens to be a big ugly bitch.
And BP, you're probably the only one who loves Cersei...other than her brother of course. I mean, with all the shitty things she does to everyone around her. The lies, the manipulation and outright dishonor of her character...I've been waiting for something terrible to happen to her since season one. If Tyrion doesn't strangle her, Danny will feed her to the dragons, and I shall laugh. Just as I laughed when Jeoffery was poisoned...the viscous little cunt that he was. Watching her lose her children one by one has been fun and all, but she always seems to be rewarded for her misdeeds. Its high time the bitch was punished for once!
But over all, I for see a few things happening. Like Danny retaking the iron throne, I don't think the Lanisters can do a damned thing to stop her at this point. I for see her hooking up with the Starks and leading the fight against the Night King and the white walkers...I mean, if fire is the only thing that really kills them aside from obsidian and valarian steel, then dragons will make all the difference in that war. And since her enemies are the Lanisters, the Starks have no reason not to side with her. Especially since Jon's good buddy Tyrion is her right hand.
Also, the revelation about Jon Snow's mother took me by complete surprise, yet made perfect sense. Though, correct me if I'm wrong, but wouldn't that make him the rightful ruler of Westeros? I mean...Ned Stark's sister was kidnapped and raped by the mad king's brother, that's what that whole rebellion thing was about wasn't it? So that makes Jon Snow a Targarian, and a Stark...king by right of two royal bloodlines. Not that I think anyone is going to find out about that anytime soon...I mean, Ned took that secret to his grave, and Bran is a long way from home.