Read the text and answer the following questions.

The Legend of Rawa Pening

    Once upon a time, there was a little poor boy came into a little village. He was very hungry and weak. He knocked at every door and asked for some food, but nobody cared about him. Nobody wanted to help the little boy.
    Finally, a generous woman helped him. She gave him shelter and a meal. When the boy wanted to leave, this old woman gave him a lesung, a big wooden mortal for pounding rice. She reminded him, “Please remember, if there is a flood you must save yourself. Use the lesung as a boat!”
    The little boy was happy and thanked the old woman.He continued his journey. While he was passing through the village, he saw many people gathering on the field. The boy came closer and saw a stick stuck in the ground. People challenged each other to pull out that stick. Everybody tried, but nobody succeeded. “Can I try?” asked the little boy. The crowd laughed mockingly. The boy wanted to try his luck so he stepped forward and pulled out the stick. He could do it very easily. Everybody was dumbfounded.
    Suddenly, from the hole left by stick, water spouted out. It did not stop until it flooded the village. And no one was saved from the water except the little boy and the generous old woman who gave him shelter and meal. As she told him, he used the lesung as a boat and picked up the old woman. The whole village became a huge lake. It is now known as Rawa Pening Lake in Salatiga, Central Java, Indonesia.

Why did the woman survive?