Young Lady Jessica acted very bravely throughout this movie (facing up to the ghost, kicking the bomb, etc), so her actions should have given Sir Simon his rest.
Great fun, no matter who the hero is...
You can't expect a sexism-free spectral arrangement in the 1600s. One man has to undo what another man did in order to help the ghost. The ghost says a KINSMAN has to do it. In this case that means MALE.
shareTo free Sir Simon, she would have to be wearing his signet ring while performing her acts of bravery.
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