Bethenny Frankel Dimitrios Kambouris/Getty Images Bethenny Frankel is mourning the death of her mother, Bernadette Birk, who died on Friday, April 19, at the age of 73 following a battle with lung cancer. The Real Housewives of New York City alum, 53, posted photos and a touching tribute on Instagram, opening up about her complicated relationship with her mom. “She was complex, in pain, isolated and had demons. She was the most stunning woman you have ever seen, who left her abusive home as quic