Amazon selling account and taxes!

Hi everyone, I live in USA and my sister lives in Pakistan. She wants me to create a amazon seller account and a saperate bank account because she wants to do business on amazon. I can give my account details to her but I’m worried about the Tax or reporting the sales ( that would be under my name or account) to IRS. She said that I don’t have to report the sales to IRS until she reaches $40k and she won’t reach that limit and she would use my personal account and not business account so tax is no issue. Is it true? Background: My husband and I file joint taxes. Please let me know how this works or if it is even legal? I have no idea about it. Thanks!