Seeking advice (adoption, adoption reversals).

My younger sister lost her kids due to drugs, alcohol etc. She signed them over to a cousin temporarily until she got her life together. During this time my sister got worse and my cousin went for adoption. I had no idea this was going on as I live in another state. The cousin that adopted them does not care for them. She pretty much collects the check and is lazy. The children aren’t bathed, the house is disgusting... NASTY! A pig wouldn’t live in it. She never has the children and always pawns them off on random people. They are forgotten at school, not always fed etc..

Do I have any rights, now that she has adopted them?

Can the adoption be reversed?

I know this is just an app but I’m hoping someone has had similar experience or works in this area.

Thanks