The baby weighed 8 lbs., 3 oz.
"John, Kelly and their daughter Ella Bleu are ecstatic and very happy about the newest member of the family," they say in a statement. "Both mother and baby are healthy and doing beautifully."
Preston, 48, told PEOPLE recently that the entire family was in major preparation mode for their new addition as her pregnancy neared its end.
"I've been cleaning out everything in the house," Preston said in September. "Ella has been helping too. She's looking forward to being a big sister."
Travolta, 56, and Preston's son Jett suffered a fatal seizure at age 16 in January 2009.