I'm thinking of my nephews being abused more obviously than I was and yet I still don't know what to do
In what way were you abused as a child?
I was once locked up in a house for a few years and couldn't move freely.
It's not too late to report this abuse to the authorities. The member that abused you and your nephew need to be held accountable. Otherwise, the person might still be abusing children and you could have stopped it.
I can't do that. I don't want to be part of a series of legal issues.
I can understand that but it is really important to report someone who is abusing children. There could be a way you can report them without being involved in any legal matters. I would mention the situation to the police anonymously.