[BigRock]

Lori is only Lady Macbeth if that analogy is used in the broadest possible sense of "Woman telling her husband to do something". Which would make every wife Lady Macbeth.

She's not manipulating Rick for her own purposes. Shane is a danger to Rick. We've known that since the first season when Shane got Rick in his sights and appeared to think about it. Lori bringing this to Rick's attention isn't manipulation, it's altering him to the reality that there's a possibly-unstable guy in their group who has reasons to want him out of the picture.