Rachel is the pot-smoking stepsister in Netflix’s “His Three Daughters,” who gets the Bronx apartment when Dad dies.

As played by Natasha Lyonne, perpetually stoned Rachel has issues, is misunderstood and is having a hard time with her siblings Katie (Carrie Coon) and Christina (Elizabeth Olsen) as they get together in their father’s final days.

For writer-director Azazel Jacobs, these three days with the three daughters as their dying dad lingers is personal.

“I’ve grown up very, very close to my parents, inspired and encouraged by them and always dreaded losing them. That definitely was a big part of the inspiration,” he said in a virtual press conference with his actors. “To confront some fears and hopes that I had before going through it myself.”

Though they exhibit an intense familiarity onscreen, the three women had never met, much less worked together previously.

“That was part of the mystery and the magic of it in a weird way,” Lyonne, 45, said. “Aza, in the first place, wrote something that was so deeply personal — but then he wrote it for each of us. But we didn’t actually know each other, we don’t have each other’s phone numbers.”

“Well, we do now,” Olsen, 35, said.

“Yeah, we do now,” Coon, 43, added.

“For me, for sure, it was this perfect storm.  I was just dying,” Lyonne confirmed, “to get to work with these guys.”

“We sat around the table and we read through the script and talked about backstory and history,” Coon said. “We all knew, by virtue of having signed up for it, our job is to build intimacy.”

As the three argue and bond, as their father gets closer and closer to death, “The job,” Coon added, “is to realize that we’re actually having a pretty universal experience — where everybody feels they’re doing it wrong.

“And also doing it right! and doing it beautifully! There’s something about getting older, and there’s something about this film — it’s about the safety net of being like, ‘I can trust that these guys can hold it.’”

“I think vulnerability is the gig,” Lyonne said. “But some conditions, you feel safer doing that.  Here, you feel invited to do it truthfully.  Because, going back to the script, it’s so specific, the relationships are so specific, that the authenticity was written into it in a way.

“I always welcome the opportunity to investigate something like the mortality of my parents.

“I mean, that’s why you’re an actor. The invitation to explore maybe something you haven’t actually experienced yet is very instructive. The very act can be very expansive and make you more human in a way. That is what I appreciate about this film.”

“His Three Daughters” is in theaters Friday and streams on Netflix Sept. 20