Abby Lee Miller is firing back at Maddie Ziegler's claims that her show "Dance Moms" had a "toxic work environment." Earlier this week, the 19-year-old dancer opened up about her time on the hit Lifetime reality show for her Cosmopolitan cover story, explaining why she left the show in 2016. "[Abby] trained me, she helped me, but also, I knew I would be okay without her and I was sick of being in a toxic environment. I was like, 'This is not for me. I can't do this.' I haven't spoken to her since." On Thursday, Abby responded to those claims in a 10-minute-long YouTube video. "What I don't understand about the pressure, about the toxic situation is if it was so toxic, why did you keep doing it?" she said in part.