Mrs Smith has always struck me as a tiny bit sinister. She still does. But she is, in her way, an honorable woman, and especially given her circumstances, at heart (which is, one assumes, part of her attraction for Anne as a friend).

Look at the arc of her speech, in her "natural tone of cordiality". She starts out by apologising for not being more open sooner, but then explains herself awfully well. Why should she risk alienating her friend, who might think she was just bad-mouthing Mr E out of resentment over the property thing, as well as losing the chance to perhaps gain a positive influence over him in that particular situation through that very friend? Makes sense to me, too.