The 18-year-old just scooped C$48m ($35.8; £29.7m), becoming the youngest Canadian ever to win such a big prize, APA reports citing BBC.
But while many teens suddenly endowed with unimaginable wealth might run wild, Ms Lamour intends to keep her feet firmly planted on the ground.
The university student plans to finish her studies and become a doctor.
"I was crying - happy tears - of course," she said at the Ontario Lottery and Gaming Corporation on Friday as she celebrated last month's win.
"I still can't believe I hit the Gold Ball jackpot on my very first lottery ticket!"
Ms Lamour, of Sault Ste. Marie, Ontario, said she had forgotten all about the lottery ticket until she heard news that someone from her hometown had won the 7 January draw.
When she went to check her ticket through a mobile app, a jingle started to play and "Big Winner" flashed on the screen.
"My colleague fell to his knees in disbelief," Ms Lamour said.
"He was yelling. In fact, everyone was yelling that I won $48 million."
Her boss told her she could leave early, but her mother insisted she stay and finish her shift.
Ms Lamour said she will "carefully" invest the majority of the jackpot with the help of her money manager father.
In fact, her dad has already given her the best piece of financial advice - it was his idea to buy the Lotto 6/49 quick pick.
Ms Lamour plans to invest some of the money to fulfill her dream of becoming a doctor without worrying about grants or loans.
She wants to return to northern Ontario to practice medicine and give back to her community, she said.
But Ms Lamour does plan to have a little fun with the jackpot winnings.
"Once school is done, my family and I will pick a continent and start exploring," she said.
"I want to experience different countries, study their history and culture, try their food, and listen to their language."
She's also hoping to abide by some of the advice loved ones have shared with her.
"Money doesn't define you," she said. "It's the work you do that will define you."