Betty Broderick -- the woman who fatally shot her ex-husband and his new wife back in 1989 -- died in the ICU Friday following a number of health issues, TMZ has learned. Betty's son, Daniel Broderick , tells TMZ ... she had a number of septic infections -- including one infection that she had years ago and came back. Plus, she had a serious fall at the Californian Institute for Women where she was locked away about 3 weeks ago ... which resulted in broken ribs. Daniel says Betty ended up in