Just a thought here - what if Nelle is Nina’s daughter & is really dead? If Nina finds out that Nelle was her daughter, that could cause her to go over the deep end & become mentally ill again. This whole burial thing to me is weird. I can see her going after Carly & anyone that “hurt” Nelle.
Think she’s dead wrong about no one giving Nelle a break. Carly did, as did Michael. Joss did also. Nelle held a grudge against Carly for a non-existent reason. Carly was not her sister, in fact was no relation to her. She only saw Carly once & became fixated on her.