In Friday's second round, Jee shot 5-under 67 and Soo carded a 6-under 66. After 36 holes, their scores are 11-under 133.
"From the beginning of the tournament I have been very confident," Jee, a rookie from South Korea, said through an interpreter.
Marisa Baena (65) and first-round leader Mikaela Parmlid (67) share third place at 10-under 134.
"It was a really good day," said a satisfied Baena. "I hit the ball very solid (and) only missed one green."
Seventy-three players made the even-par 144 36-hole cut.