The latter can be found on Harry-Mulligan-892/F at X:-14.41, Y:26.78, Z:-50.08) After this, she should be available to spawn in the swamps. Another is to build a campfire site for ghost stories. You'll have to place some charred flowers, gravestones and a bunch of iron fences, all of which can be found in the Weird Woods. (One beginning task is rebuilding her garden. All credit goes to gandalfwhi40 for finding this: To start, you'll need to Discover the Spooky Girl in her native Weird Woods and complete one of her tasks.
Update: This is pulled off of the Lego Worlds Wiki page.
