If the vet is still alive and has a service connected illness/disability that makes caring for the spouse difficult, the VA will increase his compensation ($$), in addition to possible CHAMPVA (health insurance).
If the vet is deceased, was not service connected, and the spouse is of low income, she could be entitled to a low income pension from the VA. Only problem is, if she is getting Medicaid, the extra income may bounce her out of that assistance.