It's absolutely disgraceful how they are carrying on over on the FB pages, mob mentality. Would probably been a good case study for someone studying Psychology or the like.
I really feel for the Mother, to have to deal with the brutal death of her daughter by a Family member coupled with the wrath of the public whilst trying to grieve as well must just be completely overwhelming (massive understatement).
I really believe that yes initially she did lie to the Police about seeing the kids that morning as she didn't want to be seen as an unfit Mother.
I think that when she woke up to find Willow gone she would have spoken to the brother to see if he knew where she was and then he has most likely told her that he gave them breakfast and put a dvd on at such and such a time so she has adopted that story.
I think when she spoke to the Police initially she clearly thought that Willow would be found wandering somewhere.
I also think that it's probable that when she did realise it may not be the case of Willow wandering off she probably admitted to the Police fairly early on that she had in fact not seen the kids in the morning at which point I would imagine that she may have been told to keep that to herself.
I don't think that it was a case of her maintaining that she saw those kids in the morning throughout this whole ordeal.
Anyway that's just my 2 cents worth and obviously my opinion only!!
My heart is just really breaking for her.