I never found her convincing, there were a lot of great character actors on the old westerns like Rawhide and Gunsmoke, and other shows, charectors that looked real and that you could see meeting in real life and them being part of a group, but Edith never seemed real to me, there were many moments where she could be convincing, but there were moments where you could see the actress, and many moments where you wondered about the character itself.
There’s always a level of caricature that goes along with a sitcom. I couldn’t imagine meeting anyone like Lucy Ricardo or Ralph Kramden either.