I'm sorry you are going through this. I was involved in a custody evaluation along with my husband for his children several years ago in Ramsey County. I remember being nervous, but the evaluator was very nice and it was quite relaxed. She met us at our house and talked with us. She asked a series of questions, but mainly just to get us to talk about the situation, what our concerns were, and what we thought was best for the children. We were not allowed to have a lawyer with us. We were not asked to present any documentation or "evidence". If you haven't talked with a lawyer yet, I would suggest doing that.
The recommendation of the evaluator is taken seriously by the judge. The biggest lesson I learned through our years of court/lawyer/evaluator/mediator involvement is that the court system and all involved are NOT logical or rational. They say they are there for the "best interest of the child", but they only follow the law. It will be your responsibility to do the best for your daughter no matter what the court decides. Good luck!