Shin, winless on the LPGA Tour in 2012, finished her round despite a 2-hour delay brought on by bad weather
There were 33 players still on the course when darkness forced a suspension of play.
Dewi Claire Schreefel was 7-under par through 16 holes and will finish her opening round early Friday.
Shin missed eight weeks of action earlier this year with a wrist injury. Christie Kerr, a two-time winner in Williamsburg, had a 1-over 72 in the opening round.
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