--it's likely she has celiac and some degree of villous damage.

There's probably no need for an endoscopy given the test result, unless someone wants to document to the "gold standard". The problem with many GI people who do endoscopies to take villous samples is that the villous damage is often patchy, especially early in the disease course, and many don't take enough samples or take them from the right areas (far into the small intestine, not just in the duodenum).

She should be on a gluten-free diet. And I'm betting there would be at least one more positive test result among the first degree relatives--maybe more.