The 53-year-old Hollywood funnyman is doing everything he can to help her family, including helping out financially, reported People magazine.
"Jim is doing everything he can to help. He is devastated, but can't imagine how her family must feel," a source said.
The source added that as White's stepmother and sister arrived in Los Angeles on Tuesday, September 29 to make arrangements to bring her body back home to her native Ireland, "Jim arranged for his driver to pick up Cathriona's family from LAX. Her family has access to his car during this awful visit to LA."
White's body was discovered at her home in Sherman Oaks, California on September 28. She was 28. Meanwhile, officials have confirmed that an autopsy to determine White's cause of death is still undergoing.