Today's moms spend more time with their kids than ever before, but we're also working a ton in paid and unpaid roles. According to a recent study out of the UK, mothers who work full-time and are raising two or more kids are 40% more stressed than working women with no children.

So many moms feel like if they could just add more hours to the day so they do could more they would be less stressed, but the key to decreasing our stress and maximizing our potential might actually be doing less, not more.

Tiffany Dufu is a mother of two, the founder and CEO of The Cru; a peer coaching service for professional women, and the author of Drop the Ball: Achieving More By Doing Less. On the latest episode of The Motherly Podcast, sponsored by Prudential, Dufu tells Motherly co-founder Liz Tenety that the key to achieving more, in motherhood and our careers, is making strategic choices about what you can drop.

For Dufu, who witnessed her own mother fall into poverty, financial stability was an important part of what she felt would make her a good mom. "Some women have children and they want to be at home. They want to stay at home. I had children and I wanted to put my foot on the gas pedal in terms of my career. I wanted to make money," she explains.

And before her kids arrived, she had an idea of what that would look like. In her mind's eye she saw herself keeping a clean house, sitting down to dinner with her family each night and still breaking boundaries in her career. But her first day back at work after her maternity leave was shockingly different than how she'd pictured working motherhood.

She found herself sitting on the floor of the bathroom, expressing breast milk into the toilet because she "couldn't handle both the pump and the bottle."

"It was like literally a mess and I was crying on my way home in my designer suit with like gross milk on my nice silk blouse," she explains. "It was a huge turning point because it was the first time that reality hit."

In the 12 years since that episode, Dufu has been redefining working motherhood in a way that works for her, rewriting the cultural programming girls grow up absorbing. "From the moment that you were wrapped in a pink blanket you've been receiving messages about who you are and what you should be. And that's a very kind of daunting realization for someone who feels like I did, that you're in the driver's seat of your own life."

Dufu's used that driver's seat to clear a road for other women. She's run a national women's leadership organization that's trained thousands of women to run for office, and helped so many women develop careers they are passionate about. But in order to do this, Dufu had to decide which metaphorical balls she was going to drop.

"I don't manage my kid's social calendar and that usually means that my kids miss a lot of birthday parties because we don't live in an evolved world in which people send birthday party invitations to children's fathers," she explains. "So when it comes in my inbox and I have to ask myself my 'dropped the ball' question, [I ask] is responding to this birthday party invite my highest and best use in raising a conscious global citizen?'"

If the answer is no, they skip the birthday party.

For Dufu, motherhood isn't about doing it all, it's about choosing what to do by being real about how much time is in the day and being strategic about how she invests that time. "It means that we hedge our bets and we decide I'm not going to puree this baby food today because I'm working on a better future for this child," says Dufu.

Sometimes being the mom and person you want to be means you won't be following a script pre-approved by society, but you will be free to write your own story.

To hear more about Tiffany Dufu's experiences in motherhood and her career listen to The Motherly Podcast, sponsored by Prudential, for the full interview.

You might also like:

• Hillary Frank on how to embrace your unique parenting style—and find your mom wins
• Anne-Marie Slaughter on the mental load of motherhood and why we need to be doing less
• Tone It Up's Katrina Scott on why we've been talking about postpartum bodies all wrong