The Titanic beauty separated from the film director last March (10) after seven years of marriage.
Winslet insists the break-up has remained amicable, and she is refusing to let the split affect her son, and his 10-year-old sister Mia, from Winslet's first marriage to Jim Threapleton.
She tells Harper's Bazaar U.K., "One thing I will say about me and Sam is that it's fine, it's really fine. I'm not going to s**t-fling, there's no point in even going there. It is what it is.
"We're grown-ups at the end of the day, and however hard it's been for me, it's been equally hard for him. And we have a child together who we both love - and raising him together, jointly and without any conflict, is absolutely key. It's the only way to do it, and I've really learned that with Mia."
Winslet has also been trying to refrain from talking about the split, for fear of letting her emotions out too much, adding, "As a woman, especially when you have children, one gets so good at soldiering on - almost too good. I probably had very few moments of allowing that sadness to emerge.
"I kept pushing it away, not even really sharing it a huge amount with friends. Because you know what it's like, as soon as you open that can of worms, it's so f**king big, you wish you'd never taken the goddamn lid off."