The magazine did not provide further details.
She married Garner - which gained fame from the television series "Elias" Alias - fromactor and director Ben Affleck in June 2005 in a special ceremony in the Caribbean.
The couple had their daughter Violet in December, the first in December 2005 and the second daughter Serafina in 2009.
The couple - both in the thirty-ninth of age - had announced in August last year, it'sexpecting a baby III.
Source: Reuters