Update, for those who were/are interested in hearing.
Somebody hurt my little girl, though I have absolutely no idea who. She won't say. Back in November she had a gynaecological examination and there was scarring and tearing which means that someone hurt her.
We moved homes in January to a new area of the city and have basically re-created our lives. She goes to a new school and we don't really see anyone we used to see. It just didn't seem safe anymore, especially not knowing who it was that hurt her. She hasn't really made any friends at her new school, but as she is getting more talkative and closer to her "old self", she is making progress in that area as well.
She continues to see a psychiatrist once a week and right now we share a bedroom, even though our home has two, because it makes her feel better to have me close I suppose. She is talking again, and is coming out of her shell. She hasn't made any attempt to hurt herself again but to be safe, I have basically baby proofed our home.
I really wish I knew who it was that hurt my baby girl, because I swear I would tear them limb from limb. I've joined a group in the city for parents of children who have been sexually assaulted and it is the most surreal thing I have ever been to.
Long story short, though it wasn't the news I was hoping to hear, I'm glad that I know the truth about what was going on with Soleil, and that she is able to get help with dealing with everything that's happening. She smiles and laughs now, which has been a long time coming. She's going to heal and move on ultimately, and right now I am doing everything that can possibly be done to ensure that she is traumatised as little as possible by it all. She's doing well, and will continue to do so.