The term Mary Sue really needs to die.
As I said elsewhere, Tarantula's story ends with her acting like a selfish cowardly bitch, trying to kill Nightwing herself, ultimately defeated by a Nightwing who, after resolving to the right thing, absolutely demolishes her with laughable ease.
She didn't "one-up most of the Bat family", she was a rookie that managed to keep up with them and occasionally surprise them (particularly in public venues where they couldn't respond to the fullest of their abilities). When push came to shove, Nightwing was able to defeat her while in crutches.
And she proved that, while she may have gone after people that were even worse than herself, she was a rotten person too, quite willing to kill a good man that she claimed to have feelings for, in order to avoid jail.
This is a wish-fulfillment character?
Maybe for someone that needs psychiatric help. But I don't buy it.