...And Anne does not gobble up Mrs.Smith's words blindly...

I don’t think Ann is fooled by Mrs. Smith. She can separate from MS’ account what is likely to be the facts and what is Mrs. Smith’s own prejudice views.
“Mrs. Smith did not want to take blame to herself, and was most tender of throwing any on her husband; but Anne could collect that their income had never been equal to their style of living, and that from the first there had been a great deal of general and joint extravagance. From his wife's account of him, she could discern Mr. Smith to have been a man of warm feelings, easy temper, careless habits, and not strong understanding;”

“After listening to this full description of Mr. Elliot, Anne could not but express some surprise at Mrs. Smith's having spoken of him so favourably in the beginning of their conversation. "She had seemed to recommend and praise him!"”

I think Ann judges for herself. She may always value Mrs. Smith for both her past kindness and her present contribution to Ann’s happiness, and also for her pitiful current state, but she still questions some of MS’ conducts (past and present).
I also don’t see JA giving us any information or leading us to any opinion concerning MS, that Ann is not aware of. All negative notions that I have and other people posted here were voiced by Ann herself.