The Harry Potter star was left devastated in March (12) when her mother, Roma, passed away just days after being diagnosed with lung cancer.
French spoke about the tragedy during an appearance BBC Radio 4's Desert Island Discs show, which aired in the U.K. on Sunday (23Dec12).
The actress was asked to pick a number of songs to be featured in the programme and she chose At Last by Etta James, revealing the song was played at her mother's funeral and symbolised Roma's belief that after death, she would be reunited with French's father, who committed suicide when the star was just 19 years old.
French became emotional as she said, "When my mum was very poorly and knew she was dying, she said to me, 'Well, it’s win-win, isn’t it?' I said, 'How on earth can you say that, Mum? You’ve got terminal lung cancer' and she said, 'Well, either I stay here longer with you or I go and see your dad.' She absolutely believed that’s what she’d do. So we played this (At Last) at her funeral because at last she was with him."