I don't know where you have got the 'the other Mini nanny didn't notice they'd gone' as when I read the statement she was referring to Madeleine and not the fact that she didn't notice the group had gone. This nanny was concentrating on her own group in her care so why would she be concentrating on who was going sailing?
Could you show me where it says both nannies said they went to the beach on Wednesday afternoon, as when I read Catriona Baker's statement she said they went to the beach on three occasions but apart from sailing trip couldn't remember what days the other two were on.
Cat made three statements not just her rog one (by which time she would have forgotten).
We were told by Catriona that the only days they went to the beach were Tuesday afternoon (1 May 2007) between 15:30 and 16:30, on Wednesday (the next day) at the same time and on Thursday between 10 and 11 o'clock
http://www.mccannpjfiles.co.uk/PJ/CATRIONA-TREASA-B.htm.
She is not sure whether during the morning Madeleine's group had outdoor activities, mainly at the pool; she does remember that around 1230 Madelew's (sic) father went to fetch her for lunch.
When questioned, she states that on Wednesday May 2, her group and Madeleine's group went to the beach, but she is not sure if Madeleine was in the group or not,
http://www.mccannpjfiles.co.uk/PJ/EMMA_WILDING.htmI don't care how hard you concentrate you'd notice six children being got ready and going, not to mention the gap in the room. We don't know how many children Emma had that day, but if there's 14 being reduced to 8, you'd notice imo.