as a learner driver you must be accompanied by a driver with 3 or more years driving experience and who is 21 or over. Here is more info from the DVLA: -
I had my driving test with an examiner in the passenger seat, and examiner watching the examiner in the back and my driving instructor in the back too.
i know you are allowed to have your instructor/examiner in the back, but i was more thinking of myself, my dad(who is my teacher), my sis and her baby in a carseat, in my own vehicle, as a learner, just giving her a lift - am i allowed to?
If you read "The Motor Vehicles (Driving Licences) Regulations 1999", check out section 16 para 8 and it quite clearly states that if you are driving a passenger carrying vehicle you are only allowed to carry the supervisor in the passenger seat. Other passengers are expressly prohibited, unless you are taking a test.