Brynn Catherine was born at 6:19 am on Nov. 24, weighing 7 lbs. and 6 oz.
"Nothing compares to the miracle of bringing a new life into the world," McMorris Rodgers, 44, said in an Instagram post. "She's beautiful and seems to be taking it all in stride. Our hearts are full."
Correction: A previous version of this article referred to McMorris Rodgers as vice chair of the House Republican conference. She is its current chair.