DC Comics and its whole host of characters is one of the oldest within the comics industry: that much is true. And this is why they regularly try to keep their whole stable fresh and up-to-date. After all, you can’t be telling the same stories over and over again; what was current in the 1940s has become almost irrelevant to the comics of 2017. Oh, and since we’re on the topic of things that have a tendency to become repetitive, there is no other character whose fictional biography matches this description better than Hawkgirl (and Hawkman, too, but that’s another story for another time). And even more appropriate for what I was just discussing a few sentences ago, this same character is a perfect example of how DC keeps their properties. Although the degree of success they have with this, generally speaking, is admittedly almost always a 50/50 split between it working well or otherwise. On one hand, these updates on character history at times become successful initiatives that make any given property more relatable to readers, not to mention understandable for them. On the other, though, there are instances where these same alterations to continuity cause more confusion than before. Hawkgirl is a case of the latter.
Now, don’t get me wrong, though: I like Hawkgirl. In fact, I think both she and Hawkman are two rather criminally underused characters in the DC universe. In fact, I’d completely understand if you call hooey when I say that part of Hawkgirl’s charm is her superhumanly confusing back story. So much so, that you could even think that DC just went and gave up on explaining the character’s origin and just say that every aspect of the character can be explained by her gift/curse of an endless rebirth cycle. That way, every incarnation of the character applies; it’s all just part of the whole program.
All right, if we’re sticking to the first ever appearance of the character in the funny books, then we’re talking about Shiera Hall, who was created in the Golden Age by legendary writer Gardner Fox and illustrator Dennis Neville. However, the DC universe’s continuity then becomes segmented into two by the time the 1950s ended.. By the 1960s, we now had two versions for most of DC’s characters, namely the Golden and Silver age versions. Hawkgirl was no exception to that.
The second version of Hawkgirl, which is from the Silver Age, first appeared on The Brave and the Bold #34 in 1961. At this point, the two characters will become two completely different ones, with one being the Hawkgirl we’re talking about (the one from the Golden Age) and the other better known as Hawkwoman (the one from the Silver Age).
Now, it just gets even more complicated than that afterwards, but I will save you the trouble and just say that apart from the Golden and Silver Age versions of Hawkgirl, respectively, there is a third one named Kendra Saunders who appeared in 1999, and she’s mostly the one that DC’s been using these days.