Maybe whoever wrote about it had the nomenclature confused - the terminology is similar, so I can certainly see how it's easy to mix them up.

Hyperinsulin is too much insulin, hypoglycemia is blood sugar too low.

That's what happens when the body itself produces too much insulin, driving glucose too low.

But the same condition can occur if you have hyperglycemia (blood sugar too high: diabetes), then take too much insulin, driving your blood sugar too low: hypoglycemia. When that happens with a diabetic, they immediately give them glucose tablets to bring their blood sugar back up to the normal range.

I don't know what the situation was with her though - maybe she was diabetic? Some of the symptoms of both a high and low are similar.