The Today FM producer (35) will change her name to Mairead Ronan after she weds her businessman beau Louis Ronan on Friday.
She also said she will go by her new name at work, despite having made her mark with her own name.
"I'm going to change it. I can't be two people," she said.
While Dubliner Mairead is hoping for blue skies and sunshine on Friday, she won't be bothered if it rains.
"It doesn't matter if it's a storm - I'm marrying the man of my dreams so it'll be sunny in my head," she said.
Mairead has been keeping tight-lipped about the venue of her wedding, though it will be in Louis' native Tipperary.
Louis, who popped the question last year, has organised the honeymoon - and Mairead has no idea where.
She recently revealed her eight-year-old son Dara will be taking on a special role for the occasion.
"Little Dara is best man," she previously explained. "He's been practising his speech at home, I'm the only one who's heard it … he wrote it himself.
"They had a stag party here in Dublin. Dara organised it - they went to the secret cinema across the road from Brooks Hotel to see Teenage Mutant Ninja Turtles, there was about 12 of them on it."
The 35-year-old says most of the wedding is planned and she's "excited" to walk down the aisle.
"We're nearly there [with the plans] but I do think we're probably still going to be doing things the week of it," she said.
"We've all the main things done like food, music and the dress - all those boxes have been ticked," she told the Herald.