I'm not too sure that one can convincingly tie his/her own hands behind their back. Feet, maybe, but unless you are Houdini or the Greatest Boy Scout Knot Tyer, I just don't see it being passing for authentic. It would be loose. Think about it -- how many of us can scratch our own backs, let alone do things with our arms behind us? If I tried to tie my hands in front of me, I still don't think it would be very tight. I guess I think that's a dead giveaway. For example, in the Jayna Murray/Lululemon murder, Brittany Norwood attempted to make it look real and they knew straight away that it was fishy because of the way her hands WEREN'T tied. And why stage your murder that way? Pack your bags and leave town, cut yourself and throw some blood around. I don't know... It's nefarious.
Also, why wouldn't she be with her significant other at the hospital? I understand you can't be there 24/7, but is there any mention anywhere of her having visited the boy or being there to support her boyfriend?
It sounds like this accident with the son happened and someone blamed Rebecca. Even if she blamed herself and decided to go out on her own out of guilt (or because she thought people assumed her guilt) the rest is just uncalled for. Who restrains his/herself? So she couldn't stop herself? If you really want to die, you won't anyway.
I hate to see so much tragedy happen and have someone's death sold short.