I know people like to say Leo "made her" but lets take a look at all the things she accomplished in her career 2 years prior to even meeting Leo...
(This is not 100% as she's always done alot of Brazilian fashion too, but I'm only counting the MAJOR, international work). And in 1995-1997 she worked mostly as a teen model in Brazil so I won't count those years either. (the list would be even longer. )
1998
Campaigns:
Ralph Lauren by Bruce Weber
Dolce&Gabbana by Steven Meisel
Gianfranco Ferre by Michael Comte
Missoni by Mario Testino
Chloe by Tom Munro
Valentino by Michael Thompson
Versace by Mario Testino
Covers:
Arena october
Cosmopolitan march
Vogue Brazil march
Marie Claire UK march
Elle Brazil April
Allure USA May (by Mario Testino)
Marie Claire Italy june
Vogue UK august
Elle Brazil october
Marie Claire Italy october
Marie Claire Poland december
Vogue Brazil december
Marie Claire Brazil december
i-D UK december (by David Sims) (issue dedicated to her)
Allure USA december (by Mario Testino)
Editorials:
Elle USA march (by Gilles Bensimon)
Vogue Paris march (by Mario Testino)
Harper's bazaar USA march (by Patrick Demarchelier)
Marie Claire UK march
Mademoiselle march
Vogue UK may
Cosmopolitan USA may (by Patrick Demarchelier)
Allure USA may (by Mario Testino)
Marie Claire Italy june
Allure USA june (by Mario Testino)
Vogue Germany july (by Michel Comte)
Harper's Bazaar USA july (by Patrick Deamarchelier)
Vogue USA august (by Ellen Von Unwerth)
Vogue Italy september
Vogue Russia september
Vogue USA september (by Steven Meisel)
Vogue Italia october (by Steven Meisel)
Vogue UK october
Vogue Paris november (by Michael Thompson)
Vogue Brazil december
Vogue USA december (by Mario Testino)
The Face UK december (by Mario Testino)
i-D december (by David Sims)
Vogue Italia december (by Elle Von UnWerth)
Harper's bazaar december (by Patrick Demarchelier)
Runway shows:
Issac Mizrahi,Alexander McQueen,Badgley Mischka,Balenciaga,GFF by Gianfranco Ferre,Giorgio Armani,Philosophy,Michael Kors,Chanel,Costume Nacional,Alberta Ferreti,Betsey Johnson,Byblos,Emporio Armani,Emanuel Ungaro,Sportmax,Givenchy,Valentino,Max Mara,Missoni,Marni,BCBG,Versace,Cynthia Rowley,Cerruti,Carolina Herrera,Loewe,Ralph Lauren,Celine,Christian Dior,Dolce&Gabbana,Donna Karan,Ellen Tracy,Gucci,Hussein Chalayan,Louis Vuitton,Marc Jacobs,Versus,Vivienne Tam,Moschino,DKNY,Fendi,Jill Stuart,Bill Blass,Richard Tyler,Calvin Klein,Viviene Westwood
1999
Campaigns:
Dolce&Gabbana S/S by Steven Meisel
Versace S/S by Steven Meisel
Versace Jeans S/S by Steven Meisel
Celine by Patrick Demarchelier
Valentino by Steven Meisel
Ralph Lauren by Bruce Weber
Versace F/W by Steven Meisel
Dolce & Gabbana F/W by Steven Meisel
Covers:
Arena december by Vincent Peters
Telegraph by Mario Testino (calling her the model of the millennium)
Elle Germany
W USA january by Michael Thompson
BIG UK may (issue dedicated to her)
W USA may by Michael Thompson
Numero #3 may
Elle Brazil june
Vogue Italia june by Steven Meisel
Vogue USA july by Steven Meisel ("return of the sexy model" cover)
Vogue Korea august
Harper's Bazaar USA august
Vogue Paris august
Harper's Bazaar Australia september by Patrick Demarchelier
Vogue UK september
Vogue USA november by Annie Leibowitz (Millenium special,where she posed with model legends))
Vogue Korea november
Numero #8 november
Vogue Italia beauty december by Michel Comte
Vogue Brazil december
Vogue USA December by Steven Meisel (special issue on VH1 model of the year awards, which she won)
Editorials:
Vogue USA january by Helmut Newton
Vogue USA january by Steven Meisel
Vogue UK february by Mario Testino
Vogue USA february by Steven Meisel
Harper's Bazaar february by Criag McDean
Vogue USA march by Steven Meisel
Vogue USA april by Arthur Elgort
Numero may
Vogue Italia may by Michel Comte
Harper's Bazaar may by Terry Richardson
Big may by terry Richardson
Big may by Mert&Marcus
Big x12 (the issue dedicated to her)
Vogue Italia june by Steven Meisel
W june by Michael Thompson
Vogue USA july by Steven Meisel
The Face UK august
Vogue USA august by Steven Meisel
Allure august by Rankin
Vogue USA september by Steven Meisel
Vogue USA september by Peter Lindbergh
Arena september by Mikael Jansson
Dazed & Confused september
Harper's bazaar USA september by Patrick Demarchelier
Vogue USA october by Michael Thompson
Harper's Bazaar october by Patrick Demarchelier
Vogue Paris november by Herb Ritts
Vogue USA november by Steven Meisel
Arena december by Vincent Peters
Vogue USA december by Steven Meisel
Vogue Italia december by Michel Comte
Vogue USA december by Steven Meisel
Vogue Italia december by Steven Meisel
Allure USA december
Runway Shows:
Victoria's Secret,Versace,Versus,Vivienne Tam,Alessandro Dell'Acqua,Anna Sui,Alexander McQueen,Anna Molinari,Badgley Mischka,Calvin Klein,BCBG,Blumarine,Moschino,Ralph Lauren,Valentino,John Galliano,Carolina Herrera,Jean Paul Gaultier,Christian Dior,Alberta Ferreti,Celine,Cerruti,Chanel,Chloe,Dolce&Gabbana,D&G,Costume National,Lanvin,Jil Sander,Hussein Chalayan,Gucci,Givenchy,Gianfranco Ferre,Ellen Tracy,Sportmax,Salvatore Ferragamo,Prada,Oscar de la Renta,Narcisco Rodriguez,Missoni,Miu Miu,Michael Kors,Max Mara, Marc Jacobs,Louis Vuitton,Loewe,Marni,Betsey Johnson,Hugo Boss,Yohji Yamamoto,Yves Saint Laurent,Balmain,Byblos,DKNY,Donna Karan,Helmut Lang,Tommy Hilfiger
So pre Leo :
-She had the support of all the major Vogue's already (American,British,Paris and Italia)
-Support of known industry/career makers; Anna Wintour,Mario Testino,Steven Meisel
-3 American Vogue covers in one year all at the age of 18/19.
-Already receiving accolades. "Return of the sexy model" by Anna Wintour. "Model of the millennium" by Vogue. "The Body" by Alexander McQueen.
-Already having magazine issues dedicated to her.
-Opening/closing alot of the runway shows she walked in. (sounds petty but for a model its a big thing)
-Won The VH1 Vogue model of the year award (a big awards ceremony in the 90s, Linda Evangelista won as well for example.)
-Victoria's Secret wanted her.
-Became a muse for Dolce&Gabbana and Donatella Versace.
-Was already working consistently with the biggest photographers,designers,magazines,brands etc...
Leo obviously helped her in the fame game in 2000, but I think people forget that in the same year she also signed a record breaking VS contract, had a Rolling Stone cover, an impeccable fashion career,hosting awards shows,more American Vogue covers AND dated Leo. It's not like she just rode on his fame, that's for sure. She always had her own highly successful career and has always been in demand.
I think her list in 2 years is longer than some models lists in 10 years.