Sheriff Larry Rollins says crews are developing plans to continue the rearch.
McMillan has been missing since she fell into the Lower Little River last Tuesday afternoon.
Deputies say they received a frantic call about someone falling into the river around 5:45 p.m. Tuesday near the Tradewind Subdivision on Woodwind Drive.
Her relatives told Eyewitness News the first grader went to play with a friend whose home is located near a 30-foot embankment that slopes into the river.
Officials later confirmed McMillan fell into the water and her friend ran to get help.
The Henderson County dive team began helping with the search efforts over the weekend.