Answer quickly please

Are you referring to chapter 12? Karana builds a fence using the skeleton of a whale that had beached on the island many years before. She ties its rib bones together with bull kelp, and uses wood and plants to construct a house within the fence. The only entrance to the house is a path she digs under the fence, and which she protects with stones. She even creates reed baskets and stone utensils to make cooking easier.

Is this for chapter 18

No

This is chapter 24, she tames and befriends the animals and she builds a bigger house.