Does a student allowance qualify as a "social security benefit" for restricted licence conditions?

I'm hoping someone here can help.

John has a restricted licence and lives with his unlicensed sister, Julie. John has been able to take Julie as a passenger because she's been on the JobSeeker allowance. (Exceptions to the no passenger rule include "relatives that live with you and are on a social security benefit.")

However, Julie has just started uni study and is now on a student allowance, not JobSeeker. Is it still legal for John to drive Julie around on his restricted, under the social security benefit exception? Will this be an issue with John's insurance / violating the terms of his licence?

I cannot find a solid answer through Google or reading through various government sites, and I can't find that it's been covered here.

Thank you in advance.