I generally think masculine nicknames on girls are pretty spunky as long as they are short for a feminine name. Not all of them are ones I would necessarily consider for a daughter of my own, but I appreciate them.
Some of my favourites are:
Alexandra nn
AlexWilhelmina nn
BillieFrancesca or
Frances nn
FrankieCharlotte nn
CharlieAugusta nn
Gus