The Derry Girls actress (30) said she always checked employment paperwork to see how her wages would be affected by a terror alert.
She got so used to it, when she moved to England she caused shock by asking how much she'd be paid if a shoot was shut down by a bomb scare.
"In Derry, you'll look at a contract and see if they pay you for bomb scares. They don't happen all the time: it's not like a war zone," she said.
"But some shops do have to close.
"Then, moving to England, I was looking at a contract and said to my friend, 'What would they pay you if a bomb scare happened?'
"She was like, 'What? What do you mean?'
"I thought, 'Ah, OK, so this is new.'"
Derry Girls, which had its series finale last week, featured a series of bomb scare storylines and gags.
They included Aunt Sarah, played by Kathy Kiera Clarke, sighing in the first episode: "I'm not enjoying this bomb. I've an appointment in Tropicana at 12...sure I'll not get over the bridge at this rate."
Jamie-Lee's gobby, randy character Michelle Malone makes the gag when armed soldiers board a bus unannounced: "Do you think if I told him I had an incendiary device down my knickers he'd have a look?"
The actress - who bought her own corner shop in Derry in 2017 - added that her working-class roots has always made her conscious of aspects including contract checking.
"Owning my own corner shop taught me that there's not a lot of money to be made in confectionery. I've worked since I was 16 and had multiple jobs while at school," she said.
"I'm one of the very few working-class people on a lot of the jobs I do. And I'm really proud of being working class.
"It gives me a real strength and helps me know who I am and what I'm about, and it's given me such an unbelievable drive and ambition.
"I would like to make things easier for the people coming behind me, try my best to leave the door open, whatever way I can."
The actress, who has also starred in Channel 4's prison drama Screw, also revealed her mental health battles as she tries to stay private due to her shyness.
"I've had anxiety, I've had depression. I've had ups and downs in my life, the same as everybody," she said.
"I don't know anybody who hasn't had some sort of issue... you find different coping techniques.
"Even if I'm by myself, speaking the words that are in my head out loud helps me rationalise them and take the panic out of them."
Jamie-Lee, who lives in Derry with her DJ boyfriend Paul McCay (30), added about the mental health problems plaguing the city: "There's a lot of mental health troubles in Derry. There's PTSD and some addiction trouble.
"I went to an all-girl Catholic school, but we didn't have any nuns. There's a lot of positives and negatives of growing up in a city that's coming out of a civil war. There's a lot of areas that still need help and support. But there's also a real sense of community, love and honesty within Derry."
The "community" feeling involves fans approaching her even when she's withdrawing cash.
"It's full of really warm people and really good people. You get the odd fan that oversteps," she said.
"One time I was getting money out of an ATM. Someone came over, leant against the wall and was like, 'Hey.'
"The fact I was getting money out wasn't even in their head. They were just thinking, 'Oh, there's Michelle.'
"I think they just get really excited. I'm quite shy. I'm actually a very private person, and I'm trying to maintain that as much as possible.
"I'm the only person from my group of loved ones that does acting, so I'm happy to step away from my work and step back into my usual life."
Jamie-Lee also spoke out in favour of abortion rights amid uproar in America about the proposed reversal of abortion rights.
"I feel strongly that abortion should be free, safe and legal. Because banning it doesn't stop it, it just makes it more dangerous," she said.
"It's a woman's right to choose. Some groups were very annoyed when we did I Told My Mum I Was Going on an RE trip (a play about abortion) at the Lyric in Belfast.
"They organised a protest against it before they'd seen the script. It's closed-minded ignorance."