I don't think you need to give the conclusion of killing the brother in the logline.? I also don't see any reason to mention she has 2 cloned children.? ?I would simply say something like this:

"Impeded by her own brother, a genetically enhanced woman finds she has the power to kill with just her thoughts and unleashes this power to save her children."

A biologically enhanced mother plans for more clone children, but she must make the world a place where they can survive, so she unleashes her ability to kill using only her brain, kills her brother.

A mother to two clone children plans for more clone children, but she must make the world a place where they can survive, so she unleashes her ability to kill using only her brain, kills her brother.

A mother to two clone children plans for more clone children, but she must make the world a place where they can survive, so she unleashes her ability to kill using only her brain, kills her brother.

As foxtrot25 said:
>>>>With film, you need to focus it down to laser or cherrypick from the 3 act structure.

Yep, then prune down the cherries to the one with the core hook and unifying plot line for a logline the pilot episode.

No doubt, a hard task for such a complex and extended story line as the one you conceive.? But that's what it takes to get your script read.? And only you can do the pruning because only you know your story.? We can only evaluate and suggest tweaks to the logline.