It might have helped, her telling the truth of what OP's parents and sister did to Lucy and her mother. Like she's still mad, but at least others knew what happened and how cruel OP's family was.

Hopefully, this post will ease her ghost further. Let everyone know what kind of people your family were.

What would you have done at that age?

Well what could they do? Lucy’s tormenters were older than them and I don’t think their parents would’ve listened to them at all. Their family made their bed and they had to deal with the consequences of their actions. But to punish a young child for their family’s sins is too much

the kid was like ten. at that age, most kids wouldn’t be able to stand up to their parents and might still struggle with even their older siblings. i certainly wouldn’t have been able to do anything to help at that age

Lucy is a very new raging spirit so hasn’t learned to harness rage yet.