Diane von Furstenberg, founder and chairman of the eponymous fashion label, has experienced her fair share of sexism in the workplace.

"When I was just getting started in the '70s, there were definitely times that I was underestimated because I was a  woman," she tells Inc. "But I turned that into a strength. I used it to motivate myself."

Today, von Furstenberg's empire takes in an estimated $500 million in annual revenue, with 1,500 points of sale in 55 countries. Since launching in 1970, the brand has expanded beyond its iconic wrap dress, which catapulted the designer to success. It now manufactures accessories, luggage, eyewear, and even home furnishings. DVF has outfitted celebrities including Gwyneth Paltrow and Madonna, as well as First Lady Michelle Obama.

Still, the entrepreneur can vividly recall a time when she didn't believe the brand would make it big--and encourages other women not to fall prey to self-doubt.

"It is hard to say the biggest mistake in my own career, but I think of times when I did not trust myself, or when I listened too much to other people about what I should do with my business. That was a mistake," she said.

On Tuesday, pegged to International Women's Day, von Furstenberg announced the four nominees for the seventh annual DVF People's Voice Awards. Created in partnership with the Diller-von Furstenberg Family Foundation, the awards are designed to support those who give back to women in need around the world.

Starting today through March 27, the public may vote to decide the 2016 winner, who will receive a prize of $50,000, as well as mentorship and resources to promote his or her organization. "We look for women who have shown the courage to fight, the power to survive and the leadership to inspire," von Furstenberg said.

Here are the four nonprofits up for this year's laurel:

1. Sexual Health Innovations

Founder and chief executive Jessica Ladd launched Sexual Health Innovations, which makes apps and software systems, after being assaulted as an undergraduate at Pomona College in Claremont, California.

"I went through the reporting process and found it disempowering and retraumatizing," Ladd told the New York Times. "I started thinking about what would have been helpful."

"We can end rape only if we hold perpetrators accountable," she said in a video promoting the DVF awards.

One of Ladd's many solutions is Callisto, a sexual assault reporting website for college students. Victims can anonymously post details of an assault, which the site then saves and time stamps for them. Students can later decide whether or not they wish to file a formal complaint with their school or with the police. Callisto also has an in-built matching system, whereby victims can choose to file a report only if another student names the same assailant.

To date, the service has raised an impressive $400,000 from Google.org, the tech giant's philanthropic branch. It is being tested out at the University of San Francisco and Pomona College.

2. I Am That Girl

Roughly 62 percent of girls feel insecure or unsure of themselves, according to a 2008 study from the Dove Self-Esteem fund, and at least one startup is hoping to change that.

Launched in 2008, I Am That Girl is a social network that encourages girls to express themselves, and remain positive.

"I Am That Girl is a massive community that is raising the standards for how girls treat themselves," explains the nonprofit's co-founder and CEO, Emily Greener.

The website currently has more than 700,000 users and 150 local chapters.

3. War Child

Samantha Nutt, the best-selling author and physician, is also the founder of War Child Canada, a nonprofit that aims to support children and families in war-stricken areas of the world.

"We make sure that families can actually begin to rebuild their lives and rebuild their communities," Nutt says. In addition to physical resources, War Child will provide psychosocial support and education.

Recently, the nonprofit partnered with Passport to BRITs Week, where proceeds from ticket sales to concerts -- including for music groups Coldplay and Florence and the Machine -- went directly to War Child.

4. Unchained at Last

Fraidy Reiss knows intimately what it means to be in an abusive marriage. The founder of Unchained at Last, which is the only U.S. organization dedicated to providing legal counsel and resources to women in forced marriages, started the nonprofit after escaping from such a union herself.

"Unchained envisions a world where every women is free to choose whether, when, and whom to marry and whether to get divorced," Reiss says.

The resources are desperately needed, as an estimated 3,000 cases of forced marriage took place in the U.S. from 2009 through 2011. Generally speaking, women enter these unions due to religious customs -- Orthodox Judaism, for instance -- that give only the right to grant a divorce.

"I cannot even describe what it's like to have an angel sweep down and kiss you on the forehand and then hold your hand and tell you, 'I'm not letting go until you're OK,' " said victim Ditty Weiss, who was offered support through Unchained at Last, in an interview with the New York Times.