This article originally appeared in Forbes.

Today would have been Margaret Thatcher’s 91st birthday. The Iron Lady was born on October 13, 1925. During her lifetime, she rose to become a leader on the world stage and a true ally to the United States. While she was Britain’s first female prime minister, she is more well-known for what she did in office than her sex. Thatcher fought the perils of socialism at home and communism abroad.

Presidential candidate Hillary Clinton should learn this lesson from Margaret Thatcher.

Thatcher certainly didn’t take on the feminist label and famously said, “I owe nothing to women’s lib.” Allan Mayer, her biographer, wrote, “In Margaret Thatcher’s view, her sex is an irrelevancy, and she is annoyed by people who make too much of a fuss over it.”

While Thatcher didn’t ignore her sex or the sex of voters, she did not make it the justification for her campaign and leadership. For example, she said, “I’ve got a woman’s ability to stick to a job and get on with it when everyone else walks off and leaves it.”

And she said, “Any woman who understands the problems of running a home will be nearer to understanding the problems of running a country.”

Clinton has had an uneasy relationship throughout her two presidential bids with the historic nature of her candidacy. She downplayed it in 2008 compared to 2016 until the end of her campaign. At her last campaign rally at the National Building Museum, she said, “Although we weren’t able to shatter that highest, hardest glass ceiling this time, thanks to you, it’s got about 18 million cracks in it.”

She has taken a different approach in 2016. At her first campaign rally, she mentioned her sex right away. Clinton said, “I may not be the youngest candidate in this race, but I’ll be the youngest woman president in the history of the United States.” And then her campaign released a “44 boys is too many!” video advertisement featuring girls reading letters to Clinton encouraging her candidacy. She has continued to bring up how much her victory would mean to little girls in America and made that a campaign theme.

Yes, if Clinton wins, she will be the first female president. That will always be part of her legacy. But if she wants to be remembered for more than her sex, which she should, then she would be wise to learn from Thatcher and not make that her central focus.

A true victory for American feminism would be that the first woman president is remembered for being a great president, not just the first woman president.