Her winning novel relates the long search of a daughter to find out about the death of her father, killed by a Japanese kamikaze pilot during the Second World War.
The award of the prize for a first novel raised eyebrows when it was announced on yesterday's lunchtime television news. Aficianados of the Goncourt also expressed astonishment that the award had gone for the second time in three years to the publishing house Albin Michel.
Three of France's biggest publishers - Gallimard, Le Seuil and Grasset - act as trustees for all five of France's top literary awards, and the back-stabbing politics of French publishing are traditionally regarded as no less important in deciding the awards than literary merit.
The tally of Goncourts since the beginning stands at 82 for Gallimard, 59 for Grasset and 29 for Le Seuil, with Albin the next best placed with 14 awards.
Some believe that the appointment last year of two new judges to the 10-member Goncourt committee injected a degree of surprise and openness into an increasingly stuffy and incestuous process.
The award of last year's prize to Andrei Makine, a Russian who has since been granted French citizenship, was particularly controversial. Not only was he a Russian writing in French, but he had already been named winner of the Medici prize for the same novel, The French Testament, and the Goncourt had always stood out against sharing prize-winning novels.
If the attitude of the committee has started the change, the value of the prize has not. It remains at a paltry 50 francs, far outweighed by the prestige to the writer of winning and the certainty that sales of the winning novel will soar. A Prix Goncourt can still make or break a publishing house.
The process of selection, a series of ballots which take place over a gourmet lunch at the Drouant restaurant in central Paris, has not changed either. Ms Roze's novel won on the third ballot, after the chairman - whose vote counts for double - opted against one of this year's favourites, Rhapsodie Cubaine, by Eduardo Manet, a French-naturalised Cuban writer.
Another favourite, Instruments des Teneres, by Nancy Huston, a Canadian writer who lives in Paris, appeared not to be in the running. One explanation was that the jury wanted a born and bred French winner this year to end a run of foreign and colonial writers.