The couple, who got engaged earlier this month, were close friends during their school days but grew apart in later years when Roz moved to Los Angeles to work on her modelling and acting career.
However, they quickly reunited when she moved back to Ireland last December and started dating after meeting again on a night out in the capital.
They are now expecting their first child together, a boy due in early March.
Roz, from Rathgar, said they are hoping to get hitched next summer and will be having the ceremony on home turf.
"I think I would like Ireland. Irish weddings are gorgeous and it's so accessible for friends and family," she said.
The 31-year-old added that they will most likely go "somewhere tropical" for their honeymoon.
Roz has said she is very much looking forward to becoming a mum and has "a lot of support" from her family, adding that there is "a lot of excitement in the Lipsett household" at the moment.
Although she's excited for the future, she admitted she was never the most maternal person.
The Dubliner added that she has no plans of slowing down her career after motherhood and wants to keep working.
"I was never like, 'Oh my God, I want to be a mum'. I definitely want to keep working because my mum was a working mum," she told the Herald's Diary.
"But then when I saw the scan, I just got so emotional.
"Having a baby niece, it has made me feel a whole lot more maternal, and I can't wait. But I've never been the type of person to go, 'I want this many kids'."
Roz's son will be the second new addition to the family after her older sister, Sarah, recently gave birth to a daughter.
Speaking previously about working in America, Roz described it as a "whole different ball game" where the competition for jobs was fierce.
Her younger brother, Rob, has attracted a sizeable online following through his YouTube channel where he gives fans fitness advice.
The siblings have teamed up to form The Creators Agency, which helps brands to create viral content online and recently had their first event at the Radisson Blu Hotel.
"He has lots of speakers coming in. It's great helping him and doing something together," said Roz.
"We had been wanting to do something together for ages. It will be the first of many events."