Molly Fitzgerald was born a raised in Dunshaughlin, Ireland. Her father was a fanatically militant Irish nationalist. When Molly was three years old, her father took her and her brother to the North Ireland mountainsides and asked the heavens to grant his son the power to strike down its enemies. Although nothing seemed to have happened, Molly learned during her first year at University that she was the one who was blessed. She discovered she was surrounded by a protective aura that caused random improbabilities to manifest themselves on her behalf whenever she was in trouble. Rather than return to the war-torn mountains, she used her "good luck powers" to become Ireland's superheroine, Shamrock.
Fitzgerald's career as Shamrock remains largely unrevealed. At one point, she was transported alongside various other international heroes by the alien Grandmaster to participate in a so-called Contest of Champions and paired with Captain Britain. The two disagreed with each other due to the region's history. During this Contest, Shamrock's luck allowed her to defeat Captain America.
She was among the heroes who celebrated the Hulk's presidential pardon and remarked: "Tis easy being green!" She along with other heroes from around the world helped Rom the Space Knight against the Dire Wraiths during their attempted invasion of Earth.
Eventually, Fitzgerald began a career as a primary schoolteacher and abandoned her superhero activities in favor of building a better world through education. When Molly's brother was killed in an IRA terrorist bomb blast, her father, long since estranged, asked her to come with him to the North Ireland mountainside once more. There, he drugged her and gave her to the criminal geneticist Arnim Zola in hopes that the mad scientist could duplicate Molly's powers and transfer them to her father. The process unleashed Molly's powers a thousand-fold, allowing her to escape, and Molly soon defeated Arnim Zola. Her father confronted her at gunpoint, frustrated that Molly would not use her powers in his militant quest. Unfortunately, Molly's powers defended her by making her father's gun explode in his hand, killing him. Molly Fitzgerald reluctantly returned to her former life and, presumably, her superhero career.
Molly, as Shamrock, attended the first-ever Pan-European Conference on Super-Human Affairs as a representative for Ireland. The conference was attacked by the Nazi villain Brain Drain, who brainwashed the heroes present to return to their countries and kill their heads of state. Various members of Alpha Flight raced to stop the heroes, and Northstar hoped to stop Shamrock from attacking Ireland's president; however, her powers made her immune to Brain Drain’s influence, and the president was never in danger.
Molly finally took the opportunity to retire from crime-fighting when she noticed her luck powers had finally run out -- she slipped and broke her left foot! She took up a new career as a hairstylist and ran into Captain Britain and Meggan. She agreed to do Meggan's hair for her wedding, soon becoming "the most sought-after hairdresser in all of Europe" and serving the likes of Shadowcat, Wolfsbane, and Janet Van Dyne.
She later moved to the US settling in New York City where she planned to open the first superhero salon. She tried to put on her old costume but it had been so long, it no longer fit. Trish Walker and Sue Storm became regular customers of hers. Felicia Hardy came with her niece Lou but she refused to have her hair cut. However the Trapster attacked the salon, and Lou used a blow dryer to knock him out, gluing up the Trapster in his glue. Molly then used the glue to give Lou a fancy hairdo.
She later purchased the Luck o' the Irish Pub. It was a regular haunt for the heroes of New York. One night a group of male superheroes told stories about their exes and current girlfriends while they waited for them to arrive. She put them in their place and told them to stop moaning. Their partners, all members of the Fearless Defenders, arrived and apologized for being late to the party.
