Anna lived on the side of a valley (山谷). O

问题：

Anna lived on the side of a valley (山谷). One winter, there was a very big flood, and a lot of houses down below Anna’s house were washed away. Anna’s house was high enough to escape the flood, so when the water had disappeared and the other houses were standing there with no roofs and walls and all covered with mud, her house was still quite all right. That year Anna’s was very lucky.

Her house was quite small and there were only two small bedrooms, her husband was dead when the children were very young, and she had four children, but Anna took in one of the families that had lost everything in the flood and she shared her home with them until it was possible for them to rebuild their house.

Anna’s friends were very puzzled (困惑) when they saw Anna do this. They could not understand why Anna wanted to give herself so much more work and trouble when she had already quite a lot of children to support. Life would be even harder when another family joined them.

"Well," Anna explained to her friends, "at the end of the First World War, a woman in the town where I then lived in Germany found herself very poor, because her husband had been killed in the war and she had a lot of children, as I have now. "

"The day before Christmas, this woman said to her children, ’We won’t have much for Christmas this year, so I am going to get only one gift for all of us and I am sure we will all be glad to have it. Now I’ll go and get it.’ She came back with a little girl who was even poorer than they, and who had no parents. ’Here is our gift,’ she said to her children. "

"The children were very excited and happy to get such a gift. They welcomed the little girl, and she grew up as their sister, I was just that Christmas gift. \

Why was Anna willing to help the poor（）