Kim shot a 69 in the morning session.
Of the players yet to finish the round, the closest, England's Jodi Ewart Shadoff, was five strokes back with three holes to go.
Jordan Spieth, playing with nothing to lose, gave himself another chance to win going into the weekend at the AT&T National in Bethesda, Md. Spieth hit every green in regulation and extended his streak to 29 holes without a bogey on a tough Congressional course, giving him a 5-under 66 and a share of the lead with Roberto Castro (69) before storms halted the second round. They were at 7-under 135, with the round to be completed Saturday morning.
Fred Couples roared through his first 11 holes in the second round of the Senior Players Championship in Pittsburgh, ripping off seven birdies at water-logged Fox Chapel to take the lead at 11 under.
Then the weather managed to do what the defenseless course could not, stopping the Hall of Famer with a sudden downpour that suspended play for the day with most of the field still on the course.
U.S. Women's Open
Inbee Park -9
I.K. Kim -7
Lizette Salas -4
Angela Stanford -3
Jessica Korda -3