I'm inclined to think that there are issues in Lorena's personal life going on right now which we don't know about, but which have caused her to lose her focus on being number One. Not just her forthcoming marriage, but other stuff within her family I believe, although I don't have any more info. She had a week off before one of the Majors this year for instance - not something she would normally have done - just an indication. Getting rid of her caddie certainly didn't help - the lengthy discussions they had before each shot showed how dependant she was on him for sure.