Bethenny said that her mother died of lung cancer: 'You did the best you could'

Bethenny Frankel announces mom Bernadette Birk died from lung cancer at age 73. ‘You did the best you could’ she wrote on Instagram. Former "Real Housewives" star's mom died Saturday at 73, according to Frankel.

Bethenny Frankel announced the death of her mother Bernadette Birk on Instagram. The reality TV personality, 53, shared the heartbreaking news on Saturday in an Instagram post. She shared throwback photos of her mom and a lengthy caption on the social media site.