If she has only two legs in Dragon form and a long kneck, she's technically a Wyvern (a species of Dragon in mythology) get over it. That being said, this is a game and a lot of mythological creatures are over simplified or misrepresented or misnamed.
Here are some examples:
Blizzard added Manticores in Warcraft III and World of Warcraft, but they misnamed them Wyvern's. (Either no one has bothered to point this out, or they don't care anymore since they've already made the mistake and it is too late to rectify it).
Orcs were invented by J.R.R. Tolken (like hobbits were). They are described as being just shorter than an adult man, but much broader and possibly stronger. Ash-grey, etc. Yet in most videogames and fantasy games (old and new), Orcs are usually green, or sometimes red (when the mythology of the game gives them demonic origins or they are somehow demon infused). This trend probably started when Orcs were first being used in fantasy games or videogames for aesthetic reasons, as green looks similar to grey in some shades and might have been easier to recognize in some shades, but it soon became the norm. Red Orcs and Goblins were introduced in Heroes of Might and Magic (probably some time after 3do was bought out, I've only played the Heroes III and a Heroes VI demo and Dark Messiah) as beastmen created through a combination of demon blood and human flesh. Red Orcs were also introduced in Warcraft III as demon-infused orcs.
Sorry, got off topic.
tl:dr: Fantasy games and video games rarely get their mythology right.