New mum Pink took her four-week-old son and eldest daughter to the Women's March in Los Angeles.

The So What singer made the rally a family affair, as she and husband Carey Hart brought along five-year-old daughter Willow and baby boy Jameson to the anti-Donald Trump demonstration on Saturday (21Jan17).

"We march together," the 37-year-old captioned a photo of the family on Instagram, showing her and Willow with their signs held high, with Jameson swaddled in a sling on her chest.

Carey shared a snap of his wife on Instagram holding up a sign that read "Unity, Love, Equality, and a dash of Nasty", and praised the mother-of-two for taking part in the event.

"Very proud of my wife, and it was really special to march in the streets with my family today," he wrote. "I think it's embarrassing that government has a say is what my wife or my adult daughter does with their body. I'm a big believer in staying in your lane. Don't like what I'd do or say? Don't pay attention. It isn't your business. So how about government say out of women's business?"

He later shared a sweet snap of daughter Willow asleep on his shoulders as he marched through L.A. "All of that sitting on my shoulders, I mean marching really wore Willz out lol," Carey joked.

Pink added a photo of her protest sign on Twitter, and slammed those who criticised her for taking part in the event. "I'm so tired of all of you ignorant AF (as f**k) people who say we have nothing to March about. You should be happy that people care enough to do this," she wrote as she blasted online trolls and Trump supporters.

"Dissent is the cornerstone of democracy. you've missed the entire point of having rights - or more accurately - you've probable never had to. Fight for anything. If you don't stand for something, you'll fall for anything. Anyone that doesn't like my fighting spirit, you have an open invite to kiss my entire a**. And I'm out," she wrote.

Pink later took to Twitter to share her thoughts on the historic day, in which more than four million people across the globe took part in the Women's March demonstration.

"Today was a beautiful day to be proud of. Im proud to have a voice, to have the courage to use it. I'm proud to be a woman, I'm proud of us," she wrote.