The star, 39, who gave birth to her second daughter, Frankie, on April 22, says the transition has been "great. I couldn't be better."
Speaking at a press conference for Blended, her new comedy with her frequent costar, Adam Sandler – it opens May 23 – Barrymore said, "I couldn't fake it. I'm really happy. Everything is just as good as it could possibly be."
In the comedy, the actress plays a single mom of two and said the role appealed to her because of her own upbringing.
"I had times in my life where I really needed a mom," she said. "I am now a mom. I'm going to be there for my kids. Like moms are my Achilles's heel, emotionally speaking."
As for Mother's Day, Barrymore said she and her husband, art advisor Will Kopelman, 36, celebrated in typical fashion after a full day with their 19-month-old daughter Olive: "Sweatpants, Game of Thrones, takeout," she said. "Because we were just too tired."
Reporting by SCOTT HUVER
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