How old was Greta Garbo when she retired from the movie business?

LaContessa, I suppose it depends on whether you count the last day of filming as her retirement or sometime after the release of the film when she called it her grave in response to critical reviews. The film was released on 30 November 1941 by which time she had her 36th birthday.

In a previous answer it said she was 35 so I had to use a 50/50 hint to choose between 34 and 36. :-(