Yes, but there was the feeling they were 'coached'. They also said things like Mummy or Daddy didn't argue, and any disagreement only lasted a few seconds. This was similarly spoken of by GBC. Apparently there were debriefing sessions at the Nigelaine home, there could have been many things that were reinforced as true, which the girls might not have experienced, but came to believe because the information was given to them by people they loved and trusted. Remember that in questioning one of the girls was asked about a particular statement she made, asked "how did you know that", and she responded it was because Daddy told her. Perhaps Allison did sometimes go for walks but maybe it wasn't as common or regular as has been made out.
I don't think the girls would have had time to be coached on the afternoon of Alison's disappearance. They went straight to school with Aunty Olivia. From my understanding the night "debriefing" sessions occurred later