Please have a look here about how to add a student account:
After registering, you should be taken to the first step of adding a student, which is entering all of their relevant information in order to create their account. Alternatively, you can follow these steps:
LOG IN to your Parent or Tutor account.
Go to My 11PLUS
Click on the My Students tab.
Click the ‘+ Add Student’ button on the right.
Enter all relevant details, including the date of their exam, and their 2 school choices (you may choose unknown if you do not know).
After adding a student, you will need to assign them the tests you would like them to take.
You can add another student by following the same process.