In GOF, Ron gets second hand dress robes...but ginny got???

[Samantha]

No: HPFGUIDX 135197

Hi Potterphiles!
 In GOF, we learn poor Ron has to have tatty second hand dress robes, 
which of course he is mortified to wear. BUT when Ginny goes to the 
Yule Ball with Neville, what is she wearing? Because, she wouldn't 
have gotten dress robes(even second hand ones) because she wasn't of 
age to go to the ball. Also, when she is seen at the ball, no one says 
anything about her robes. Is this a case of the only girl getting 
pampered and her poor brother getting the shaft?

Snapeo'phile