I have never known a husky to turn his/her nose up at a tin of sardines in spring water (or olive oil if you have to NOT sunflower oil). Over the last 10,000 years or so 90% of their diet was fish when in their natural habitat. Has the owner tried her on raw foods?
I have one of the fussiest dogs on the planet - and easily goes a couple of days at a time - but his weight is good. Also another thing to try is a raw whipped egg, scrambled egg etc.
What sort of foods has the owner tried? Can you give us a little more information.