To be honest, I've found all of the blanket/jumpers/backpack references slightly odd. I don't feel references to any of these is something that would lead to LE finding the children. Even if these items were found (I know the blanket was) unless the children are found with them then it's sort of not an important detail. I understand LE need every bit of information but..... In the case of the jumper, when did DM notice they were missing? Where were they missing from? The wardrobe? Was it felt the children took these with them? Without dropping them? It's an odd situation but surely more likely to be *not* linked to the children's disappearance? Sometimes I notice something has gone missing but actually have no idea when I last saw it. Could these jumpers have gone missing sometime *before* the children went missing?
Re the backpack. Had it ever been determined what this was used for? School? Bits and bobs? Sleepovers? How was it noticed to be missing, so quickly? Was it always kept in the same place? I think with children it can be even more challenging to know something is missing. You might notice something isn't where it normally is, but it could be left at school, in the car, outside, at a friend's house etc.
Such specific details yet we're still unclear exactly what the children were wearing that morning.
JMO.