I know this goes against popular opinion, but I honestly don’t think she was “lying” or being intentionally untruthful. That initial report says she “saw” MS, but every subsequent report where she is asked about it, she says she heard her or she thinks she heard her. She never gave specifics on seeing her (did JS get out of bed? Where was Maddie?) but she does get specific about hearing her (heard movement in the kitchen, assumed it was Maddie). I don’t see anything that would make her want to back away from that lie, if it was a lie. I chalk a lot of it up to all the anxiety and stress that would be building up in the hours of waiting for police and then the hours of working with them after they arrived. I wouldn’t expect any report to be 100% accurate at that point, or any point really.
The same goes for saying “we” dropped her off. I think she might even say “I” in one instance. Despite saying “we,” she also repeatedly talked about Stephan taking MS to school or how JS slept in. She keeps saying “we” even after it’s established that she didn’t take MS to school. It seems like it’s just how she talks.
Also as a caveat: I don’t quite mean that she wasn’t lying or couldn’t be lying, and more mean that the in the set of circumstances, I don’t think her language means she was definitely lying.