Christie vs Batgirl
Barbara isn’t quite as skilled as Cassandra so this would be a closer fight. In pure hand to hand combat I dare say that Christie may even have the slight edge here. Batgirl’s never been quite as impressive as some of the other Bats. That said, she has quite a few gadgets to help compensate for that. Her explosives will keep Christie on the defensive for the whole match and will never allow her to get comfortable. That’s enough of a disruption to ensure that Christie is completely doomed here. Batgirl wins.