Regarding the abuse discussion, I think it is relevant to know about AS's history of abuse. Most people who are abused learn from that, become very strong and are very careful to not repeat that behavior. However, most people who are abusive were abused themselves. The relationship with RS has given me the creepy feeling, and I am very curious about what AS was exposed to because it could give us more of an idea of how she treated the children. And to what extent. For example, (I have zero evidence of this and am just thinking hypothetically) if AS was sexually abused or had inappropriate physical boundaries with RS, the chances of her doing the same are higher. If she was never abused in that way, then the chances are close to zero. If the abuse was very psychologically/ emotionally damaging, then the chances of her doing the same are higher...
Although most victims of abuse do not repeat the behavior, it doesn't mean knowing about abuse a potential suspect endured is unimportant. I understand people feeling sensitive when discussing such things, but being abused does increase the chances of becoming abusive. It does not mean it will happen, and it probably won't, but a person is more likely to be abusive if they were abused. Especially when it comes to sexual abuse and incest. It is extremely rare for someone to become a sex abuser if they themselves were not also abused (like practically zero chance.)
That being said, understanding and excusing are very different. I do not think past abuse can ever excuse someone from hurting someone else. But it can help explain why, and what the victim may have experienced. And can help in the healing process for the victim as well. And, hopefully, can inform mental health services, Child protective services, legal decisions, etc...
So... just had to share my thoughts on this as a person who has worked on the mental health side of juvenile corrections, in other words, with kids who have been hurt so badly they hurt others, with some rare exceptions...
Sociopaths, that's a whole 'nother thread
Editing to add: I'm still sending my love and prayers to Elaina's family! Justice for Elaina is coming! Keep focusing on the love you have each shown through this horrific time!