the queen has a huge pain threshold (remember chicks have higher ones than us) she can take quite a beating, i mean, she took a fucking spear in the neck and was still walking, i reckon it would take a couple of shots to get her down.
indeed it would take a few shots from the plasma cannon, but factoring location as always, a shot at the face or any other weaker part i dont know of could instantly kill her.or she would keep moving like a bug for some time before she dies.(alien resurrection)
agreed, a shot to the face would prove fatal, as for the rest of her body then i beleive she is fairly resistant to a point of sustaining quite a few attacks.