For me personally, I feel that TM's sister is sharing some good background information that she knows about what happened when she was in her sister's life before they stopped talking.
It is pretty clear to me, that AM had control over TM, of which, one of the things that happens to women being controlled by a man, is that they cut-off ties with certain family members and only allow certain family members to have contact.
I also find AM's brother has a lot to share about the history within his family, and how AM's mother was so much closer to AM then she was with the other children. He also shared the issues within their own family and what they all have gone through over the years.
This is such a complicated cases in so many ways. So much bothers me about this case regarding all of the adults that surround these three beautiful girls. However, I have to put that all aside, and pray as hard as I can that the two children are found safe.