I ruined my family by calling CPS

I (38M) have two nieces: Mary (5, turning 6 in January) and Alice (16F). Mary has mid-functioning autism. My sister, Sarah, is a single mom, and I help out whenever I can. I normally go to their house to watch them because it's safer, and it's not fair to expect Alice to babysit Mary all the time.

Over the past year, I've noticed something unusual. Mary seems very clingy to Alice but also appears to be scared of everything, if that makes sense. For example, Mary will sit on the couch cuddling with Alice, but she'll often look down and seem to dissociate. She spends hours in Alice's room with the door closed. When I ask Alice what they’re doing, she just says, "Oh, we're just hanging out."

Alice gets Mary new clothes whenever she goes shopping and takes her everywhere. Mary sits on Alice’s lap whenever she wants, and Alice lets her. Honestly, it seems like Alice really loves her, and she spoils her quite a bit. They're always seen cuddling.

Mary has always been a quiet child, but lately, it’s become much more pronounced. It’s something I’ve been trying to figure out. I’ve noticed some strange behavior with Mary recently. She started pulling out all the hair from her dolls, ripping their heads off, and tearing off their limbs. There’s only one horse toy that she keeps safe. Whenever I ask her why she does this, she just starts crying. She also wets herself constantly and wets the bed frequently without telling anyone. She would always randomly, get naked for no reason. She would always touch herself in that way.

I started talking to Sarah about this, and she said, "Oh, it's just normal behavior for kids around that age." It all seemed very strange to me, so I decided to call CPS. And there is a massive investigation and it turned out that Alice was doing things like that to Mary. Now Sarah and nobody else will talk to me in the family. And I currently have full custody of Mary. Sarah knew the whole time, I don't know what to do because I want my family back. Alice is in a jail and is waiting to be sentenced.

Edit1 She's not being sentenced, but we're waiting to go to court. We don't know what her sentence will be or what her charges will be. But she is arrested in jail. We haven't even had the first court date. We are still waiting for a court date. But she was arrested. Also, from whatever one said I don't think I'm going to ever. Let them move my life again.

Edit2 Alice was never abused. I wanna know how I know. This is because she said it. She is just a Psychopath