picking up toxic parent's behaviors

Just sad whenever I see my younger sis rage and lash out the same way our mom used to with us.
Also sad cos I understand her since I do it the same way when I'm really at my limit. But since im a mom now too, i do my hardest not to make it a common occurrence like my sister does. Its hard to unlearn bad behaviors but at least I have my husband to step in when it's all too much and help me de-stress. But my sis doesn't have anyone and everytime i see her she's an even worse younger version of our mom and i worry for her and her future relationships with people. Funny enough tho, she lives with our mom who's grown older and calmed down and now whenever my sis is angry it feels like watching the past but with the roles reversed with my mom being the one to walk on eggshells around her lol. Anyway we both never intended to become duplicates of our mom. I know my mom didn't intend for that to happen either. But now i feel even more pressured to be the perfect parent so I wont regret how my own daughter would turn out in the future