Jamie Lee Curtis didn't have an "inkling" that her youngest child was trans.

Jamie Lee Curtis

Jamie Lee Curtis

The 'Halloween Kills' star and husband Christopher Guest were surprised when their daughter Ruby came out last year but the 63-year-old star admitted she can now look back on the 25-year-old video editor's life and recognise some signs.

She said:"I knew Ruby had had a boyfriend. I knew that Ruby had used the word bi. But gender identity and sexual orientation — those are two separate things. And I knew that Ruby played female avatars in video games.

"But when you ask, 'Did you have an inkling that Ruby was trans?' I would say no. But when I replayed Ruby's life, I went, 'Hmm, that, that, those, hmm.' "

Ruby found it "intimidating" to come out to her parents, but they were very supportive, although she couldn't bring herself to do it in person after summoning them together.

She recalled to People magazine: "It was scary — just the sheer fact of telling them something about me they didn't know.

"It was intimidating — but I wasn't worried. They had been so accepting of me my entire life."

Ruby left the room and texted her mother.

The 'Knives Out' star continued: "I called her immediately. Needless to say there were some tears involved."

Ruby admitted she may have come out as trans much sooner if she hadn't had a ""negative experience" with a therapist after years of thinking she was "different".

She said: "When I was about 16, a friend of mine who is trans asked me what my gender was. I told them, "Well, I'm male." After, I'd dwell on the thought. I knew I was — maybe not Ruby per se, but I knew I was different.

"But I had a negative experience in therapy, so I didn't come out [as trans] immediately when I probably should have. Then, seven years later, still being Tom at the time, I told the person who is now my fiancé that I am probably trans. And they said, 'I love you for who you are.' "