We tried to help her, but she 'shooed' us away.
The horse is a 'shoo-in' to win the race.
a 'shoo-in for' the tournament/job/award
(..) Get away from there. Get away from there. He'll be after you. Go on, into the house. Into the house. Shoo, shoo. Good-bye, Mr.Jefferies. See you tomorrow. Uh-huh. And don't sleep in that chair again. (..)1954 Rear Window