Why does Jessie kill herself?

Following lecture, I really did not have a clear cut opinion as to whether Jessie killed herself to hurt or relieve her mother. I think it is clear, by Jessie's comment on page 18, ("I'm cold all the time anyway"), that the underlying reason for her suicide is to relieve herself of the emptiness she feels. But yet, I feel that Jessie kills herself to, in a sense, teach her mother a lesson as well. Here's why: Jessie makes lists, has a clear cut routine, and wants to break the pattern that her life has become--this is a lot of where her pain comes from. So, when she begins to make lists for her mother, plans for what to do after she's gone, she is, in a sense setting her mother up for the same pain and torture of routine and predictability. On page 20, Jessie's mother asks, "Your birthday's coming up, don't you want to know what we got you?" to which Jessie replies, "You got me dusting powder, Loretta got me [...] Right?" Apparently Jessie was right. And at the end, we see that Mama begins to follows Jessie's plan by calling Dawson immediately after she hears the shot. In a sense, she is continuing down the same path of predictability that caused Jessie some emotional pain.