From the conversation between Rebecca and her mother, Rebecca's keeping all the courtesy was only a superficial mask.
Rebecca was staring at Avery as if she did not want to let go of Avery's subtle expression, and she kept her graceful smile, "If you're angry, I'm sorry for that. I'm so thoughtless. When my mother told me that, I didn't think that's right. As your friend, I want you to stay in the country. Then we can be relatives. My uncle is the richest person in the country except for my father, and he can protect you and promise the glory of your life. I didn't think much about it. I'm so sorry."
Rebecca's every word was in light of the benefits of Avery. If Avery refused her kindness, she would be considered as a mean person.
Avery would probably have believed Rebecca's words if she hadn't changed. But she has heard the conversation between Rebecca and her mother.