The 31-year-old, who raises son Aleph with husband Benjamin Millepied, has told her friend she is happy with just the one child, reported Showbizspy.
"She still complains about how crazy she was during pregnancy. She couldn't wait to get back to her normal routine and diet, which includes two glasses of wine at the end of the day!"
Portman recently tied the knot with Millepied, whom she met on the sets of her Oscar-winning film "Black Swan".