We have a very active parent community and we would love to keep parents "in the know" after their youngest child graduates. We have resources on the resource board (RB) that would be helpful to parents of alumni as well. For example, a link to the athletic schedules, business directory, our scripture memory program, newsletters, etc.
They still have access to the system to access their child's grading information, so why not give them RB access? Parents of grads are as much, if not more sometimes, apt to donate than their children who recently graduated, which would increase our donor base instead of cutting them off as soon as their child graduates.
I don't think we need a separate board, but giving Parent of Alumni access to the Alumni RB, or even the Friend RB, would be amazing.