Thank you everyone for the great advice and supplying some information that we were not aware of.
We both joined Avis Preferred and our booking is showing on the app.
We booked via BA Holidays,but we are not too bothered about the option to change our car.
It all sounds as though all is fine regarding us both driving. and thank you for your reassurance.
One final question -
Am I correct in assuming we don’t need to take out excess insurance?
Thanks again for your help.