this could’ve happened because they didn’t end the ouija session and didn’t say “goodbye”, so the spirit is still connected.

your sister and her friends drove her to it, they get the vengeance. your parents were hateful and excused the behavior, driving her mother to her death. vengeance. you, however, have never wronged her.

maybe set up a seance of your own. print out a nice picture of lucy again, but don’t edit it. set out some water or a drink, and other things on the board to summon her. maybe put some bandaids on there, since she keeps saying “stop killing yourself”. add some protection for yourself, like herbs or a ring of salt so she can’t leave the circle.

summon her again, but this time, apologize on behalf of your family. apologize to her and her mother. and then end the session. say something like “rest now, lucy and lizzy rogers” and make sure the planchette goes to “goodbye”. should put the spirits to rest.

burn the dummy too for good measure. if supernatural has taught me anything, it’s always burn the remains.