How long do I have to wait till I can sit next to learner driver after a drink driving ban?

First of all, your brother must be over 21 and have held his driving licence for at least 3 years. Now if the drink driving ban has expired, then your brother should be able to supervise his girlfriend when learning to drive. This is because you need to have a valid driving licence when you are accompanying a learner driver and if your brother is still disqualified from driving, then he will not be able to supervise her. The best thing he can do is find out if the driving ban has been lifted and get his driving licence back if he doesn't have it.

It is also worth mentioning that you need to display 'L' plates when supervising/teaching a learner to drive and the learner needs to be insured on the car they are driving.

Do you have to be fully comp on your own car to sit in it with her???