PASADENA, Calif. — Actress Hannah John-Kamen never had trouble saying what she thought, even as a kid. “I was assertive and a little bossy,” she admits. “Every time my friends used to come around for tea or something, I used to write a script and used to make them dress up and we’d put on performances. And I’d charge the parents about 50 pence to watch. We’d write out tickets and everything,” she said.

It’s not an accident that the execs at the Syfy Channel chose John-Kamen as the intergalactic bun-busting bounty hunter in its new thriller, “Killjoys.”

The beauteous Hannah in her black-and-blue mini-shirt and black ankle boots may look fragile, but that’s pure deception. She and her cohorts on the show trained rigorously for their parts. “Lots of physical training, stunt training and military training. So I know how to handle a gun. My favorite prop was my gun,” as she flashes a wide grin.

The youngest of three, John-Kamen is the daughter of a forensic psychologist and a former model-secretary, and seems to display the best of both her parents.

Her father is Nigerian, her mother Norwegian, and while she says her mother can be stubborn, her father has schooled her in precepts that she clings to in a field that can bend beliefs.

“My dad’s always taught me that you’ve got to be grounded. I am assertive, but I don’t get disheartened by rejection because it’s part of my career; it’s part of my life. It’s going to happen. You’ve just got to stick to who you are. You have to be who you are. Never change that for anything, and I think being assertive in that point, absolutely I will take that.”

John-Kamen was just a child when she experienced the worst trauma of her life. Her mother suffered a mini-stroke when Hannah was 10. She’s recovered fully, but John-Kamen says her mother’s illness forced her to mature a little more quickly. Her older sister (who’s now a doctor) took over temporarily for their mom, but it was the tight family unit that persevered, she says, seated on the verandah of a hotel.

She always knew she wanted to be an actress, and her parents never questioned that. Even when she left home at 18 to study drama at the Central School of Speech and Drama in London, they didn’t worry. “I was so excited but petrified. All I wanted to do was go to London and train. It was amazing because everybody around me in my class was just like me as well, so I wasn’t on my own in that. We got to meet everybody in the class, and I ended up living with six people in my class the first year, so that was fun. We all bonded instantly.”

She landed her first acting job in her third and last year of school. Though she played a murder victim in a modern-day version of “Whitechapel,” she even managed a few lines in that first series. She followed that with ‘The Misfits,” “Happy Valley” and “The Hour,” in which she played a prostitute.

While John-Kamen, 25, is comfortable with her career, she longs to concentrate more on her personal life. “I’m single,” she sighs. “I did have a sweetheart, but I’m currently solo.

“I want to focus on the sweetheart side — finding somebody. That’s something that I think is important in life. My mum and dad said you need to find time to meet somebody. Whenever I’m in a role, it’s all I think about. But it’s definitely something I need to work on.”

She harbors no rules against dating actors. “I have been with a couple of actors before. It’s tough. It’s really tough. I’ve been with someone who’s not in the industry, and it was wonderful, so that’s all I’ll say. I never say ‘never.’ You can’t dismiss something before you’ve actually tried it, because everyone’s different. It can get competitive. That’s what I’ve had experience of — not from my side. Then equally being with someone who’s not in the industry, we’ve had our issues as well with something else. It’s just the person, really.”

Meeting prospective beaus is not difficult, she says. “What’s really wonderful about being in London, it’s very much like in the film ‘Notting Hill.’ You will meet someone in a coffee shop, on the street. People DO talk to each other. I remember I met somebody in a coffee shop, and he owned a bar business, and it can be that very surprising, erratic time of meeting someone. But in our careers you’re constantly just around actors, directors and writers. It is a bit tough. So I do want to work on it. I need to sit down and figure it out.”