There's alot more to the story of Pandora then that and remember that she managed to keep the essence of hope and that is important to Gryffindor I think - she also represents mystery and injustice done to innocents but hope & bravery in adversity and afterwards too. I think a character with that name would be a cool idea. Plus there's lots of interesting angles we could use - for example, as you both pointed out 'setting loose the evils upon hogwarts' or 'the box' - i say, why not? 😉 It'd make a good story and of course it'd be an accident, she's not a Slytherin afterall 😛
BUT - if it's not really a popular idea, we can go with anything else you want 🙂 I'm fine with anything, it was just an idea and I explained it now 🙂
Where is everybody else from Gryff btw? It seems kid of empty 😖