I agree, their accounts match too closely. Imo, NM and SH are consummate liars, with years of experience at deceiving family and friends. SH being with NM since 15 yrs old, these kind of twisted relationships, I always imagine is like a cult.
As SH has visited the home numerous times, it's easy to recapture a scene in your mind that you've put into practice so often, maybe even within days before the fatal day.
I'm in two minds at present like most here, either SH, with child, remained out of sight and hearing until Becky would be subdued and placed in car (SH knowing full well the plan though).
or, SH gave her child a treat, sat her in front of t.v./put her down for nap on sofa, then she went upstairs and chatted with Becky while NM crept up behind and grabbed her. He is quite short, doesn't have the reach a bigger man would have so it was difficult, I'm assuming. Anything like this scenario is near impossible to prove unless NM changes his mind and gives another version of events.
Becky fought for her life, she KNEW this was serious and his threats to kill her were now being played out. He could have released her at anytime and said it was a joke, a cruel one at that but no.
Also, I'm not buying it was accidental, NM's plan was to kill Becky at one stage after abusing her.
NM allegedly stabbed Becky 15 times after death, the rage must have been electrifying. Stabbing can be a substitute for rape also. Was SH present? Did she participate?
It will be interesting when it's revealed how much physical evidence (fingerprints, DNA contamination) on tools, Becky's body and injuries etc. forensics has picked up on by SH.
JMO