Saoirse Ronan had done some stage work before filming this movie, and the heavy makeup combined with hot stage lights had caused some spontaneous acne eruptions. Rather than covering it up, make-up artists Jacqueline Knowlton and Ronan convinced the writer and director Greta Gerwig to leave it visible to differentiate this movie from most other coming-of-age dramas full of teenagers with perfect skin. Gerwig concurred.
Saoirse Ronan has said that the most difficult word for her to pronounce with an American accent was "perfect."
Greta Gerwig has said that she was the polar opposite of her lead character "Lady Bird" when she was growing up. She was strait-laced and not at all rebellious.
According to writer and director Greta Gerwig, the first draft of her script was 350 pages long, which would equate to a movie nearly six hours long.
Saoirse Ronan and Greta Gerwig first met each other at the Toronto Film Festival in 2015 when Ronan was promoting Brooklyn (2015) and Gerwig was promoting Maggie a un plan (2015). Ronan had already read Gerwig's script and instantly connected with the title character. When both women discussed the script at length in Ronan's hotel room, and she read the essential part aloud, Gerwig knew she had found her "Lady Bird."