Student rental income

I have a (new) client who bought a property jointly with another unrelated person for the purpose of housing their children (A&B) who were going to University.

The house was big enough for A&B plus three other students.

The three other students paid rent each month and the parents of A&B also paid rent on behalf of their two children.

Is the rental income paid by A&B's parents taxable?

It would seem strange if I bought a house for my child, paid rent into a rental bank account each month and had to be taxed on that money. However if I bought the house jointly with a friend then the money I lodged into the bank would be income for my friend.

So do I treat 50% of A&B's rental as taxable income?