Sherrock entered the fixture on the periphery, knowing two wins would likely be enough to move her comfortably within qualifying range.
The 28-year-old scored solidly against Collins but was unable to hit the doubles when she needed to, leading her to pay the price.
Meanwhile, Keegan Brown will face a nervous wait to see if he has secured a Tour Card after suffering a 6-5 defeat to Stephen Rosney early on.
Brown has put himself in a strong position having tallied seven points but will need to stay patient as the day plays out to see if he has done enough to earn a card.
Rosney advancing to the next round will see him face 2012 World Championship runner-up Andy Hamilton, who claimed a 6-3 win over Shaun McDonald.
Elsewhere, former World Cup of Darts winner John Henderson opened his Sunday with a 6-5 win over Ryan Murray and will take on Stephen Burton in the next round.