Final answer:
The Apache woman agreed to let Bright Morning and Running Bird sleep at her house because she wanted to put the girls to work.
Step-by-step explanation:
The Apache woman agreed to let Bright Morning and Running Bird sleep at her house because she wanted to put the girls to work. The passage states that the Apache woman directed her efforts against Anglo settlers, which suggests that she saw an opportunity to have the girls help her with chores or tasks around the house. The options of the Spaniards paying her, her being lonely, or her disliking the Navajo are not supported by the information provided.