Cats can be so amazing, can't they ? I have had some that were prolific hunters, but never one that has caught a bat. Obviously she was proud of herself, too; since she brought it in for you as a special gift. (which you declined to eat).
It is interesting how cats (and sometimes dogs) will bring you in the bird or mouse that they have caught.
Cats usually bring in living prey they have captured so that they can teach their kittens how to hunt for prey.
She probably sat there and watched you chasing that bat around , muttering softly to herself, "He's never gonna get it. He has to learn how to pounce way better than that."
Also, it sounds like your adult bat was much larger than the one that I caught. The wings were definitely wider than the bat's body was long; but certainly no where near a foot or more in length.
I guess the one that I had must have definitely been a baby bat.