Thanks for the images David,
I showed here both photos and she just can't remember what the plane looked like from the outside, however she did favour the Britannia. She remembers the plane departed Athens in the afternoon which matches a BOAC departure in the timetable (page 20) posted previously, in which case it could have been the Super Connie, however there is every chance it could also have been a charter or BOAC could have changed the scheduled plane to be the Britannia. She also recalls the plane had square windows and there were about 80 people on board so we know it was one of these two aircraft.
Thank you, CT.