She should have died hereafter meaning.

"This line has caused some debate. Four possible meanings are (1) she should have died after the battle when there would be time to mourn properly; (2) she should have waited for me, seeing that my death is so near; (3) she would have died at sometime, either now or later; (4) she should have died after the battle for now, with her gone, I know I shall not win. The first explanation seems most logical."