The blogger will exchange vows with fiancé Paul Quinn in just three months and says that while it's been 'all systems go', she's not turned in to a bridezilla just yet.
"It'll be here in no time!," she told VIP Magazine. "I'm so excited. I'm not a bridezilla just yet - maybe ask me again a month before the wedding!"
The fashion and beauty star, 28, has been busy planning the big day since fiancé Paul popped the question in July last year, and revealed that their proposal was actually a little more traditional than you might imagine for an Instagram star, with Paul asking Rosie's stepdad for permission first.
"We headed up to Howth Head with Harry (their three-year-old son)," recalls Rosie. "Paul pulled into the shop to get ice cream, and secretly called my stepdad Billy to ask his permission."
"It was a sunny day and we went for a walk then, he was behind me with Harry in the buggy, and when I turned around, I looked at them both and Harry had the ring box on his lap. I just burst into tears and Paul was like 'is that a yes?'."
Already well along with wedding plans, Rosie enlisted the help of event planners Frog Prince to help her visualise her day, as she says she was never 'one of those people' who had a scrap book of their wedding.
"They knew our style so came back with something very laid back, with a little bit of glamour. It's all about the candles, flowers and lighting for me."
As Rosie's father Peter passed away when she was just 18, her stepdad Billy will do the honours of walking her up the aisle on the day, but the bride has ensured she'll have her father with her in other ways as she says her vows.
"We'll have a photograph of him (Peter) up on the altar... Just so I can see his face and feel like he's part of the day."
"I hope to do something with the wedding favours with regard to the RNLI, because dad drowned and they were fantastic, so I'd like to give back to them in some way. My uncle, Dad's brother, will be there too, which I'm delighted about because he's my closest link to him now."
Read Rosie's full interview in this month's VIP, in stores now.