not to repeat what I've already shared in my reply,
while overall it does not look like mange, that waist-line sort of resembles a possible mange pattern.
So, let's feed her well and observe. It fur loss begins to progress, esp. in one of common mange patterns, maybe, repeat the course.
But it could be a combination of factors, from malnutrition, to nursing, to some other mites.
So, let's feed her and observe.