The 37-year-old married Rocknroll in December 2012 in a secret ceremony, reported Entertainmentwise.
Winslet was previously married to Jim Threapleton for three years and has a 11-year-old daughter with him. She then married director Sam Mendes in 2003. She has a 8-year-old son with Mendes. They separated in 2010.
"Kate knows how much Ned wants to be a father. She thinks they would have the most adorable kid together, so they're planning on getting pregnant by the end of the year. Having a child together is her absolute priority," a source said.