When I first saw this butterfly in the garden I saw the double-pupilled eye spots and thought it might be a gatekeeper. But we don't have gatekeepers this far north and closer inspection showed the plain hind wings and lack of white spots on the underwing. So it is a female meadow brown after all. Most have a single eye spot but double-pupilled individuals are not rare.
Compare it with a couple of female gatekeepers photographed in Somerset. They have orange colouring on the hind wings and white spots on the underside of the hind wings.