I wonder what young Erica thought would be different at age 20 that she would consider talking to Carolyn? I work with kids all day, everyday. Majority can't fathom how they will be at any point in the future...emotionally, employment ideas...anything. Such insight into a developmentally disabled 12 year old's internal awareness. Also, lets not pretend that an adopted parent is good with their child associating with their biological parents. Casey never says that she is not okay with Erica being with Carolyn, always saying that Erica doesn't want to. Reality is that Erica probably expressed a curiosity to meet her biological parents. Most adopted parents would discourage it, especially at Erica's age, but due to Casey also being adopted and not meeting her bio parents, she allowed it.
Casey is teetering on being an adopted parent and someone who was adopted. Once Erica left the meeting with Carolyn, Casey probably grilled her with questions that made Erica uncomfortable...probably to the point that future meetings with Carolyn would feel more of a hassle than they were worth. This probably caused major friction between Casey and Erica (possibly Sandy too, but probably not) The act of meeting birth parents while living with adopted parents equals that of committing adultary, at least from the adopted parents perspective. They are in the frame of mind that "we gave Erica everything and she goes and wants to meet this stranger who claims to have some kind of connection!!" If a parent is crazy enough, this act could be seen as unforgivable, which leads to anger and whatever act happened after that. My profiling for the day