The actress, who played Zuzu in the Christmas classic, told ABC News that even though she attends 20-30 showings each holiday season, the end of the movie still gives her "that tickle in my throat."
It's touching, she added, seeing others feel the movie's impact, too.
"It's an emotional rollercoaster," she noted. "It's quite exciting because I know it affects people. It's wonderful when fans say how this movie has touched their lives. It's a thrill."
Seventy years ago, the Frank Capra-directed film hit theaters. The plot centers on George Bailey (Jimmy Stewart), a husband and father who has always made great sacrifices to help others. When he's down on his luck, he decides everyone in his life would be better without him, and he decides to commit suicide. However, his guardian angel, Clarence (Henry Travers), intervenes and, in an effort to save him, shows him what life in his hometown of Bedford Falls would be like if he'd never been born.
Though the movie takes place at Christmastime and its release date coincided with the holiday season, "It's a Wonderful Life" underperformed at the box office. However, it was nominated for five Academy Awards, including a best director nod for Capra, a best actor nomination for Stewart, and best picture.