The New York-based model-turned-food blogger wed British restaurateur James Marshall in 2012, but the couple is said to be preparing for a divorce.
A source tells the New York Post's Page Six column, "Elettra and James are divorcing. She has been spending the summer focusing on her work as executive food editor of Refinery29, her website Impatient Foodie and writing a book. She has also been traveling and spending time with her mother, Isabella, at the family home on the south shore of Long Island."
Wiedemann, 32, has yet to comment on the report.
She is Rossellini's only child from her brief marriage to Jon Wiedemann, a fellow former model-turned-Microsoft executive, in the 1980s.