Then quickly, for such a short, portly, elderly person, she disappeared. (Para. 7)
Meaning: Although she was short, over-weight and old, the woman disappeared all of a sudden.
for: prep. despite
For all his faults, we like him still. 尽管他有错误，我们还是喜欢他。
For all your explanations, I understand no better than before. 尽管你作了解释，我还是不明白。
Please notice that "for" in this sense is usually followed by the word "all".
disappear: vi. go out of sight
The sun disappeared behind the clouds. 太阳躲进了云层里。
The man disappeared the same day the crime was committed; no one could find him.发生犯罪的那一天，那人消失了，没有人能找到他。
The money disappeared from the bank; no one knew who took it. 那笔钱从银行里消失了，没有人知道是谁拿的。