Sofia Coppola's daughter Romy Mars is giving all the behind-the-scenes details on what it was like growing up as the famous director's daughter ... and some of it is shocking.

Responding to a TikTok user who joked Romy was "written by" Sofia, Romy clarified that she was, in large part, raised by babysitters ... or as she calls them, "many different women in their 20s" ... and one of them allegedly gave her marijuana when she was just 11 years old!

According to Romy, 19, one of her babysitters offered her the illicit substance before bed.

Romy said, "We smoked together on the fire escape and talked about her boyfriend's mommy issues until I fell asleep."

Absolutely wild ... especially when you consider that Sofia JUST came out in full support of her daughter's online videos.

Sofia referred to her daughter's online presence as a "persona," telling Elle ... “She’s a performer in a way that’s really fun for me to see.”

Wonder if this latest clip will make Sofia change her tune ... Romy has been open about her childhood previously, but more so in a self-deprecating way.

For instance, one of her earliest viral videos from 2023 featured a story in which Romy was grounded for trying to charter a helicopter from New York to Maryland for a dinner.

Romy is the eldest daughter of Sofia and her husband Thomas Mars.