A quaint little village would probably be quite a culture shock so she'd be better off staying in London.
Is Acton over budget? If she's like to be on the tube, then anything along the district line is going to be pretty expensive. Along the northern line, South Wimbledon (the unglamorous part of Wimbledon) might be achievable. Morden would definitely be doable - not glam but has supermarkets, a little side road with some restaurants, the lovely Morden Hall Park (a National Trust property).
For a more villagey location rather than town like Sutton, Cheam Village is nice (zone 5, trains to Victoria and London Bridge, very green but a well stocked little high street with a Little Waitrose, Sainsbury's Local and a bunch of independents, library etc).
Carshalton Village is very picturesque with fab pubs, a Co-op, Sainsbury's Local and a few smaller shops. Lots of greenery, library and I know the leisure centre there even does special OAP classes. Zone 5 with trains to Victoria and the Thameslink + London Bridge trains from Carshalton Beeches.
Further West, the stretch between Wimbledon down to Surbiton is all pricier.
I don't know West London.