Do you think I should stop holding a grudge against my mum?

O.k well my mum didn't do a great job at raising me and my brothers. She was in a rut and decided that to keep having kids would get rid of all of her problems.. She was in a very bad relationship with my father, and had just lost her mum, so I know it would have been hard for her, but why would you keep having kids when you are clearly not in the right state of mind for it and also in a very bad environment. Kids are not dolls. She ended up having 4 kids all under the age of 6, and she could not handle it. She made a lot of mistakes with us. Now i'm almost 19, my brothers are 20,17 and 15 and then I have an 11 year old brother and a 4 year old (half)sister. We have a lot of problems, and she just really doesn't see where she went wrong. She has told me before that she kept having kids because they were cute when they are little, and she told me she kept having kids because she wanted more girls. She had 4 kids in an unstable environment just for these reasons? Did she ever once think of how it would affect us? No, she was just thinking about herself. And that I can't get over.