Rosie Napravnik isn't worried about history. She is, however, working on her chemistry - with a horse named Mylute in the Kentucky Derby.

Two years after achieving the best finish by a female jockey in the Derby, she will try to become the first woman to win it.

Napravnik's pursuit of the milestone comes a year after she became the first female rider to win the Kentucky Oaks, the second-biggest race on Churchill Downs' marquee weekend.

Mylute is a 15-1 shot to win the Derby on Saturday (Sunday AEST), but his last win came in December with Napravnik aboard.

That performance offered a glimpse into her ability to get the most out of a horse, something she has shown in being the leading rider at four tracks.

"Mylute will definitely come from off the pace because that's his style," Napravnik said.

"That's not a bad style to have when the race is a mile and a quarter (2000m). It's very long, so if you can have a horse that can stay relaxed in the first part, that's definitely to your advantage."

For her part, Napravnik has been more relaxed preparing for her second Derby appearance. That hasn't been easy considering the barrage of questions about her attempt to do what six women, including herself, have failed to do in 138 previous Derbys against male jockeys.

Having gone through the Derby experience in 2011 while guiding Pants On Fire to a ninth-place finish, 25-year-old Napravnik feels more like a veteran the second time around.

"It's nice to have the experience of when I was here two years ago," she said. "It's a little less overwhelming and I know what to expect.

"Winning the Kentucky Oaks last year was probably the greatest moment of my career."

As it turned out, Napravnik's breakthrough victory aboard Believe You Can in the Oaks was just the first of several big moments. She rode Shanghai Bobby to five wins including the Breeders' Cup Juvenile at Santa Anita, helping the colt claim the two-year-old championship.

A couple of months later she climbed aboard Mylute at Fair Grounds Racecourse where the horse won by nearly 11 lengths.

Napravnik went on to be Fair Grounds' top rider for the third straight year, adding similar honours at Laurel, Pimlico and Delaware Park.

"We're lucky to have her," trainer Tom Amoss said. "It may be a bit surprising that she was available for the Kentucky Derby with what I thought about her being very much in demand. But their loss is our gain."

Napravnik is all smiles when it comes to Mylute.

"He feels great, he's acting great and I'm very confident heading into the Derby," she said. "Hopefully, we can make history."