Credit: Marc Royce/Us Weekly

Denise Richards is head over heels for Eloise Joni, the 5-week-old daughter she recently adopted (who joins big sisters Sam, 7, and Lola, 6, from the actress' previous marriage to Charlie Sheen).

"She's brought so much joy, and I love her to pieces," Richards, 40, tells the new issue of Us Weekly (out Wednesday). "She is a cuddle bug. She loves being hugged and held. She's such a beautiful little baby and little soul."

Though she's "been with her since the day she was born," Richards admits that the adoption process was far from easy. "Some people think if a celebrity wants a baby, they get one the next day. The adoption took two years, and there were times I felt discouraged, times when I got close to adopting a baby and it fell through. But I knew the right baby would find us."

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Currently on good terms with her ex ("We talk every day"), Richards adds that Sheen, 45, has spent time with baby Eloise. "He knows how much I love, love kids, so he was very supportive," the actress -- whose memoir, The Real Girl Next Door, is out July 26 -- tells Us. "Charlie is truly very happy for me. He knows I always wanted more kids."

For more on Richards' new bundle of joy -- including how she broke the adoption news to Sam and Lola, plans for a baby shower, and much more -- pick up the new issue of Us Weekly, out now!