The former S Club 7 singer, 37, said her girls were "her life" and she found it hard to read the comments slating her parenting skills.
"Parenting is always going to split judgement and you never have all the answers," she told Essentials magazine. "I would never do anything to intentionally harm my girls."
The mum to Amelia, four, and Minnie Blossom, one, faced critisim on social media in September 2015 when she was pictured leaving her daughters alone in her car while she popped out to run errands.
Stevens added: "Whatever you do as a parent, you will be judged by other people.
"You can only do your best."
Stevens said she had previously put pressure on herself to be the "perfect parent", but has learned to stop self-criticising.
When the photos emerged of Stevens leaving her daughters alone in the car first emerged, parents took to social media to publicly condemn her decision.
Rachel Stevens shouldn't be surprised at the reaction after leaving her kids in the car unsupervised. Anything could have happened.— John Kelly (@ardjohn21) September 23, 2015
At the time, Supernanny's Jo Frost also waded in on the debate, but disproved of the public shaming.
"I'm sure @MsRachelStevens is now aware that her parenting choice was not a smart one but truly so fed up with celebs being publicly shamed," she wrote.
I'm sure @MsRachelStevens is now aware that her parenting choice was not a smart one but ..truly so fed up with celebs being publicly shamed— Jo Frost (@Jo_Frost) September 20, 2015
It's the tone of this public parenting police I don't like,
Stones and glass houses. Lets teach,love and educate.September 20, 2015
After Frost tweeted, other mums and dads agreed with her and admitted to being part of the "public parenting police".
One mother tweeted: "I'm sure we've all done it, there's a lot worse she could have done, leave her alone."
"People are demanding that Rachel Stevens be jailed for leaving her kids in a locked car for 10 mins. My Dad did this all the time," tweeted another.
On the Government's website it states: "The law doesn’t say an age when you can leave a child on their own, but it’s an offence to leave a child alone if it places them at risk.
"Use your judgement on how mature your child is before you decide to leave them alone, e.g at home or in a car."