She was a successful actress in the 1950s, known for films like "The Fountainhead" and "Hud." After a series of personal tragedies, including the death of her first husband and her son's brain injury, she turned to her faith and became a Catholic nun.
However, it's important to note that Patricia Neal did not actually become a nun. She continued to act and won an Academy Award in 1981 for her role in "The Right Stuff." She remained a devout Catholic throughout her life.
It's possible that you're thinking of a different actress or that the information you received is inaccurate.