Batgirl is practically and essentially a female counterpart to Batman, who is some bloke who lives in a cave and dresses like a bat to fight crime. The Batman comics were accused of having homosexual characters simply because he lived together with his sidekick Robin. This prompted later writers to give him girlfriends such as Vicki Vale, Catwoman and a female counterpart called Batwoman.
Kathy Kane is practically the first Batgirl and she used very feminine accessories. She wore yellow and red and was later given a niece called Batgirl. She’s called Bette Kane and had blonde hair. In hindsight, a dark-haired or blonde Batgirl might be nothing new. The actress who played Barbara Gordon wasn’t a natural redhead and Alicia Silverstone portrayed a blonde Batgirl.
Those were years before Stephanie Brown became Batgirl herself. A Batwoman character was looming around before Kate Kane officially showed up. One of them was a reformed Catwoman which makes some rhyming sense and that she became a more sympathetic, even heroic character as of late.
Interestingly with Stephanie Brown, she had numerous precedents. She wasn’t the first blonde Batgirl as Bette Kane was the first. She wasn’t the first female Robin as Carrie Kelly got there first. She ended up being a very successful combination of both in a way.
Barbara Gordon is probably the most iconic Batgirl, making multiple televised and merchandised appearances in a row. But she’s not the only red-haired Batgirl as Kate Kane shows. In this case the latter is known as ‘Batwoman’ but the design is oddly reminiscent of an earlier proposal for Barbara when she was supposed to get out of her wheelchair and resume that title.
Then that happened in the New 52 which was ultimately undone in Convergence. Someone on Mindlessones pointed out that Barbara Gordon is something of a second tier character. She often gets outclassed by other characters and nobody can write a good Batgirl story.
Much less a Batgirl story that doesn’t hinge on a tragedy thanks in part due to the Killing Joke and even Alan Moore, who wrote it, regretted it. Batgirl isn’t a bad character but there has to be something done with her or otherwise. She might as well be redundant.