On a raw diet dogs tend to lose more body fat that they can have from a kibble diet. But she really won't starve herself, like Tanza said the barfing before eating could be from "empty tummy" syndrome. My dog does sometimes vomits in the morning if we sleep in, he'll go outside and munch on grass and then throw up the grass and bile, it's just from having an empty stomach for a longer than normal period of time.
Your vet has checked her out, you can have them run a stool and blood sample again just to check her out; depending on your vet though they may or may not try an prescribe a kibble food - a lot of vets don't like/prefer raw diets because they haven't learned about it.
Another thing with raw is it also has more moisture content so dogs on raw tend to drink less water. Try not avoiding the kitchen, you can be in the kitchen with her and praise her while she is eating - or does this discourage her? You could also try hand feeding her for a bit.
Alternate options is you can give her Satin Balls, they work wonderfully, to help add weight to dogs that are under weight. Here's a link from a post on here to how to make them,
Maybe you could post a side view of your girl? Some basenji girls can be really dainty and petite so your girl might just be on the slight side.