Barr and team-mates Rachael Simms, Rhiann Macleod and Barbara McPake lost both their matches and now sit eighth in the 12-team standings with two wins and five defeats.
They lost 10-4 to Russia, the game turning in the fifth end when their skip Anna Sidorova took out a Scottish stone to score three points and take a 5-2 lead.
And they went down to Canadian rival Rachel Homan, who completed an 8-3 win for the hosts with a late steal.
Three teams lead with the standings after seven of 11 matches - Canada, Switzerland and Sweden all losing just one match.
Defending champion and Olympic bronze medallist Eve Muirhead is not competing at the World Championships because the Scottish team trials clashed with the Sochi Games.
© Sportsbeat 2014
- Sports & Recreation
- Anna Sidorova
- Rachel Homan