The child was born on September 26 and the couple has already found a name for the young tot, the People magazine reported.
"We are proud to announce the birth of our daughter, Olive Barrymore Kopelman, born September 26th, healthy, happy and welcomed by the whole family. Thank you for respecting our privacy during this most special time in our lives," the couple said in a statement.
Although rumors of pregnancy began swirling in February, Barrymore, 37, never said a word, preferring to let her June wedding portrait speak for itself. In it, her husband an art consultant gently cradles his wife's growing baby belly.
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