In Florence, June 2008, Diane von Furstenberg hired Alonso for her "Cruise 2008-09" collection and months later was called to New York for the Spring-Summer 2009 fashion shows.
At 21 Alonso became Spain's new top model, chosen to be in the Victoria's Secret 2008 fashion show held in Miami.
Only two Spaniards, Esther Cañadas in 1997, and Eugenia Silva in 1998 and 1999, had previously participated in the Victoria's Secret fashion show.
[4][5] She has walked for Bottega Veneta, Luisa Beccaria, Brian Reyes, Nanette Lepore, Oscar de la Renta, Tory Burch, Cynthia Steffe, Luca Luca, Diane von Furstenberg, Lela Rose, Prabal Gurung, Abaeté, and Resort 2009 Diane von Furstenberg.
[7] She is the face for Agua Fresca de Rosas fragrance by Adolfo Domínguez and appears in its TV spot.