But the celebrity who rolled down the window and wished his best to the newlyweds was none other than Prime Minister Stephen Harper.
Kelly says Harper then became, for a few minutes, the 16th member of the wedding party, posing for photos with the bride and groom — 23-year-olds Jocelyn and Patrick Sullivan of Ottawa.
She says it's been a goal of hers to get her photo taken with a celebrity, and now it's "mission accomplished."
Kelly says it didn't sink in until the reception later that day how rare it was to have Harper in a wedding shoot.
The 22-year-old photographer says the prime minister became "the talk of the reception."
I didn't have to tell anybody to smile when I was taking photos of them," Kelly said.