"We feel conflicted because we want her to see it," she said. "We want her to see the success of her granddaughter. But for the sake of her health ... she's been alive for so many years without knowing. I think maybe that's part of the factors that made her live that long. But I don't know. I will continue to play by ear."
Before anyone agreed to finance "The Farewell" in the way she wanted to tell it, Wang shared her personal story in audio form on an episode of "This American Life." (New York-based indie production company Big Beach eventually came aboard and will team with budding financier Votiv on Wang's third feature, the sci-fi adaptation "Children of the New World.")
To make the film, she fought battles every step of the way, like the notes she'd get when pitching the project to studio execs. Notes urging her to hew closer to conventional Hollywood storytelling and structure -- adding a love interest for Billi, for example, or giving her a lesson to learn.
"They were like, 'But what are the stakes? An 80-year-old Chinese grandma? Who's gonna care?'" remembered Wang. "Now the film's out and people are like, 'Oh, my God, it reminds me of my grandma, I was sobbing,' and I'm like, 'THANK YOU.'"
For Lum, who was coming off mostly comedic parts in a nascent feature film career, "The Farewell" presented a chance to tackle her first dramatic and lead role.
The Queens native was raised by her Chinese American dad and grandmother after her mom, who was Korean, died at an early age. As she read Wang's script, Lum felt a familiarity not only in Billi's relationship with her Nai Nai but her feelings about Asian American identity.
"I forget what the origin is," she said. "I think it's a Norwegian word, and it means a longing for a time and place that no longer exists. I think with Lulu's story there is something to be said about remembering a time, a happy moment, a home where you felt like you belonged."
Billi struggles to recall that sense of belonging as she returns to a China she knew as a child. The distance Billi feels between her American life and the customs, values and even language of her Chinese relatives echoes throughout "The Farewell," which is in both English and Mandarin.
Lum drew on her relationship with her own grandmother -- without whom her "Awkwafina" persona wouldn't exist, she says -- to portray Billi's close bond with her Nai Nai, which helped her slide into character with little rehearsal time once the five-week shoot began.
"My grandma always nurtured the weirder things I used to get made fun of in school for," she said. "I would come home and cry and she would tell me, 'You're not weird -- these are the things that you'll realize make you special.'"