Thus, she is assuming responsibility for the childrens' death, as if she herself had killed them. Similarly, Christy is killed while on a route home he took specifically to do a favor for her. Again, Annie "assumes" responsibility for Christy's death, given that it was because of her that he was on the route that ultimately led to his death.
Annie's decision, conscious or not, to assume responsibility for her family's death is not an uncommon coping mechanism. For many, the idea that life can deal such unfair and random blows can be overwhelming. By believing she "did it," she avoids much worse pain, that of accepting the fact that life is sometimes cruel and incomprehensible. If she believes she was responsible for the deaths, it provides some semblance of structure and order to life to protect her from life's further cruel blows.
Assessing what Annie bereaved prior to the suicide is inextricably tied to the latter issue of why she committed suicide. While the obvious driver to the suicide was the death of her children and her husband, Annie's suicide had another driver. In several instances after Christy had died and was attempting to communicate with Annie, it was evident that at the point when Christy came the "closest" to communicating with Annie, she became the most distraught. For example:
When Annie was near the gravestone, and Christy kept saying "I still exist," she eventually broke down as he kept pushing her to acknowledge him
When Christy was near the purple tree and Annie was near her painting of it, as he kept trying to "connect" with her, she eventually poured fluids on the paint realizing he would never be with her again
As Annie was writing in her journal and Christy was trying to communicate, she was able to write until the point his "presence," which she knew was not real, was too much for her and she crumbled up the paper.
It is likely that these moments brought her closest to the reality of her losses, that he would never be with her again, pushing her closer to suicide.
Annie's grief and mourning were evident. First and foremost, it was evident she had made a prior suicide attempt by slitting her wrists, as evidenced by the scars on her wrists. In addition, she was psychiatrically hospitalized and there was a fleeting reference to her "not talking for a month." In addition, her normally well-done hair became limp and unkept and her skin color was grayish, reflecting that she was not caring for herself, a common grief response. In most of the scenes prior to her suicide, she was always shown alone; isolation is another hallmark of grief and mourning.
It is difficult to say why Annie had a favorable attitude toward suicide. In the end, when she comments to Christy that he "never came to her side" (paraphrase), it appears that her suicidality was a function of feeling isolated - not just physically but psychologically. In making that comment, it is implied that she felt Christy did not "understand" her pain; he commented how he felt he needed to be strong and perhaps she needed company in having him "be with her" where she was in her pain. Perhaps she just wanted an end to the pain - Christy ended it by being strong, and she wanted an end too. The movie did not have any overt signs that would