vicissitudes

1. N-PLURAL You use vicissitudes to refer to changes, especially unpleasant ones, that happen to someone or something at different times in their life or development. 变化; 变迁[正式] [oft N 'of' n]

Whatever the vicissitudes of her past life, Jill now seems to have come through. 不管过去经历了什么世事变迁，吉尔现在似乎已经度过难关了。