我的两个孩子在同一个账户上，应该怎么办？

You should have two different accounts for your two children. If right now they are sharing an account, you should create a new account for one of your children.

To do so, please：
1）Write down the code of the textbook that one of your children is using. (It is at the top of the textbook image)

2) Unclaim one of the textbooks from the existing account (use the "Unclaim" option in the bottom of the left sidebar. Don't worry, we save the data when you unclaim).

2）Then, use that code to create a new account for one of your children.