I can't see anything wrong with Mrs Fenn's statement, in fact I find it somewhat lucid.
She clearly identifies a child crying on the Tuesday night, going out to her friend Edna Glyn on the Wednesday and of meeting with the Tranmers on Thursday morning. Carole Tranmer for her part confirms the visit on the Thursday, of going for a meal to Lagos thereafter returning to 5g where she saw a man exit from the last gate belonging to the ground floor apartments into the private alley which ran along the bottom of the gardens. She states that they left Mrs Fenn around 6.30pm.
It should be noted that the McCann's apartment (5a) did not exit onto the private alley but directly onto the public road. Thus the man Mrs Tranmer saw did not exit from the McCann's apartment even though she initially thought he had done so.
I’m not implying that Mrs Fenn was anything other than lucid, and I hope you don’t think that.
From the little I have read about her she seems to have been a feisty lady in full possession of her mental faculties although suffering some frailty.
This caused her son some concern about the unwarranted media spotlight she found herself under.
It is not what Mrs Fenn said when interviewed, it is the way it has been recorded in the files posted on the internet.
The contradiction lies in her saying nothing unusual had occurred then further on the behaviour of the man seen by her neice being so furtive it was reported to the police.
I do not think scribing her statement from English to Portuguese then from Portuguese back to English has helped.