Thanks, George. I have read that before and I don't think it addresses this situation because once she verbally quit, she only reappeared over a week later after hearing that the President (who received her resignation) left the organization. She reappeared as if nothing happened and has regained her position (which now, arguably, is also the role of President until another can be elected, since that office is now open).
Also notable: it is not common practice for this group to formally "Accept" resignations once given.