If she does get a “full tuition+room+board+stipend”, then all or nearly all of her college costs are covered, right? So then there is no concern about stacking or not (note that FA + scholarships cannot exceed the college’s cost of attendance anyway).
Obviously, the effective value of this scholarship depends on how much FA she would get otherwise. If she would otherwise be no-FA at an expensive college, it is worth quite a bit. But if she would get maximum FA at a generous college, then this scholarship would effectively be the value of direct loans and work earnings expectation that is replaced.
Is this a college-specific scholarship, or an outside scholarship, and how much effort would it be for her to apply for it?