Can be found: Floating around on one of the terrace in the Zero-G section where Isaac has to disable oxygen supply to get pass a fire.
I hope you're happy. I never wanted to come here, but you had to drag us to this shithole! And now look what's happened. My baby girl turned into... something... I had to... how could you... how could you leave us alone? Do you hear me? I HAD TO KILL MY BABY GIRL!