AE was not trying to discredit Sheila. She was trying to incriminate Jeremy by pretending she knew Sheila well enough to claim it was impossible for her to have committed murder. She was the one using anecdotal incidents for her own ends.
Well, it would have been interesting to see what she'd have said had she been trying to discredit her. She'd have achieved far more by saying kind things about her. As I said NOT very insightful.