There's actually a female Nightwing-ish alias used by Harper Row you could refit. [b][url=http://www.comicvine.com/bluebird/4005-83111/]She goes by Bluebird now...[/url][/b]

[img]http://static.comicvine.com/uploads/scale_super/3/39027/3646105-bbiu2waceaairqq.jpg-large.jpg[/img]

She obviously uses guns, the wiki had this to say about her...

[b][i]"A young Gotham City electrical engineer who wants to assist Batman in repayment for protecting her brother and her from an assault, much to Batman's frustration."[/i][/b]

~KL~