But she still didn't think the repetative sound of an electric saw was weird - especially when there was no DIY to show for it. She didn't think NM's sudden desire to buy lots of cleaning products and make a single room in their hovel dirt-free was weird?
Let's not forget, SH was the one who said
http://www.bbc.co.uk/news/uk-england-bristol-34506138
If she wasn't implicit in the murder, why would she tell the police that she had heard Becky leave the house?
If she thought it was Becky she heard, then she must have known exactly where NM was at that point or she wouldn't have known exactly who was stomping and banging the door.
We all know Becky didn't slam that door as she was dead.
So either SH made that up .......
or she heard someone bang the door (which could only have been NM carrying the body to the car) so why didn't SH consider that it might have been NM? Surely she'd have investigated the stomping and banging, especially as he would have been outside for a while if putting a body in a car. She didn't say she 'thought' it was Becky, or 'assumed' it was Becky, she said she heard Becky leave the house. Alive. She couldn't have done, we all know that.
The fact she lied to the police about Becky leaving the house, tells me she knew all about what had happened