Man thats weird. Usually the finance dept buy's the money at a certain (lower) rate and then sells it at whatever they can get for it. It's one way they make money.
Maybe they have had a rash of re-fi's and knowing her good credit they decided to avoid losing the loan to refinance by just dropping it to a realistic #. Thats what I suspect, because there is no way no hell they were just trying to be nice.