Can a piece of clothing be "iconic"?

Fashion historians would insist it can, surely, and point to a host of women's outfits: Marilyn Monroe's white dress flying up as she stood over an air vent in New York; Audrey Hepburn's little black dress in Breakfast At Tiffany's; Jackie Kennedy's pink suit that she was wearing when her husband was shot during a Dallas motorcade in 1963.

That last example is more famous for the shocking event that took place while the woman was wearing it, the fact that Kennedy refused to remove the blood-spattered suit after the assassination of her husband, or have the bloodstains cleaned. "Let them see what they have done," she is reported as saying.

Nicole Mary Kelby's story focuses on the idea of the iconic outfit: the fact that it's women who dominate in this category, and that it's women who design and produce it. Coco Chanel was the mistress of this design, but it was legally copied by the American fashion house Chez Ninon for the First Lady. In this novel, Kelby imagines the back story of one of the seamstresses who helped make it, an Irish émigré called Kate, to try and tie in the fate of the president's privileged wife and this lonely girl from Cork.

Except that it doesn't quite work like that. Kate has left her single father behind in Cork, come to the States to make her fortune and has wound up sewing outfits for the well-heeled clients of Chez Ninon. The fashion house is run by two elderly women, "the Ladies", Miss Nona and Miss Sophie, of faintly scandalous backgrounds. The head is Mr Charles, who, impressed with Kate's dedication and skill, suggests that she go into business with him. But Kate cannot make up her mind about what she wants. To stay with the Ladies, or take a risk?

Hanging over this is, of course, the prospect of Kate meeting Jackie Kennedy, but this never actually happens, although she has a couple of near-misses, when sent on errands or to attend appointments that the First Lady always breaks. Kelby has done her research thoroughly, but sometimes it's hard to see what the point of it all is: we learn a good deal about how to make clothes and the intricacies of the arrangements between US and Paris fashion houses, with a glimpse of Coco Chanel herself thrown in for good measure. But without that interaction between the two main 'stars', we're left with two very different women whose lives will go in very different directions.

Kate is also being wooed by Patrick Harris, a young butcher whose late mother helped Kate get her job at Chez Ninon. Kelby poses quite nicely the other dilemma Kate has, this time about Patrick: should they marry, she would have to give up her work at Chez Ninon and take up her place in his shop. Kate is known as "Queen" by the locals, who presumably feel she is grander than she should be, and Kelby lightly suggests the fallacy of believing that closeness to grandeur or fame isn't the same as having it for yourself.

Ultimately though, this novel is too slight. The concept is highly marketable and appealing: the background to one of the most famous outfits of the 20th century. But the story behind it has nowhere to go from that beginning, and Kelby's focus on Kate's Irish background, while attempting to imbue some kind of narrative tension with a "will she or won't she" romance with fellow Irish émigré Patrick, offers no fresh insight or surprises into the history of the diaspora.

Similarly, Kelby's prose style is a little too simple and a little too patient, as though she is worried her readers will fail to comprehend the complexities of the plot or the machinations of the various design houses. This also suggests a lack of substance in the narrative, that it's taking its time because it doesn't have that much to say. Kate steers clear of scandal surrounding the president's marriage, just as she steers clear of many things. She is a largely passive heroine, whose one act of rebellion is to eat cakes and drink champagne in a hotel after Kennedy stands her up for a fitting yet again. Sadly, it's not nearly enough.