
the link by Cava seems to have lots of useful and accurate information.
I'm not sure of the circumstances around your sister getting a husky but it seems shes rescued it? What behaviour is the dog showing for you to ask about temperament?
I own 2 huskys and although they have really different characters this is what I have found of the breeds temperament as an owner. The first thing is that they are incredibly friendly - towards everyone they meet and have absolutely no loyalty to myself of OH if a visitor walks through the front door. They are also generally friendly towards other dogs. Huskys have strong independent personalities and so do need a very firm hand. If they think they can get away with something they will and that includes manipulation their owners! :-) Mine have occasionally showed dominant behaviour towards people (although never aggression), particularly if they are not 'dog' people and arn't sure how to react to a huskys enthusiastic welcome and can be dominant towards other dogs (particularly my bitch). As I said mine have never shown aggression towards people and rarely towards dogs but our vets have told us about two they see (different owners) that have bitten their owners several times because of weak handling and the dog taking advantage of this. They are also generally quiet dogs, mine don't bark at the doorbell or the phone or at people walking past the house but do love a good howl every now and again.
I'm sure youre aware as from your OP it seems your sister has a husky but they also cannot be let off lead unless in a completely secure area and a garden must also be completely secure. Our girl has actually kicked a hole in a fence panel kung fu style in order to escape.
To me though they are the best breed in the world, nothing beats a husky cuddle or hearing them howl and sing for no other reason but pure enjoyment!