During Monday's episode of the Armchair Expert with Dax Shepard podcast, Williams, who shares daughter Matilda with the late actor, reflected on their time together after Shepard shared his own memories of Ledger.
Williams and Ledger began dating after meeting on the set of Brokeback Mountain in 2004 and welcomed Matilda in 2005. After three years together, the couple split in 2007.
Williams has spoken about her relationship with Ledger previously, stating in a 2018 interview with Vanity Fair that she felt "radical acceptance" from Ledger.
In addition to Matilda, Williams is also a mother to three children with director Thomas Kail, according to People.