It's good to see you back, I hope you had a nice time with your family.
It really is ironic that her sister was more of a burden than a help. Of course Natalie didn't want to lie to her parents by telling them she can still feel Zoey being with her. But by Zoey being angry on her parents feeling like she was always left out fed Natalie with her anger which made her have to stay in the psych ward.
Melinda losing her Grandma like that is really sad. But it was also a great way to teach Melinda the way to differenciate between ghosts and living people. Being one of the only ones who can see ghosts can make you feel lonely. Everyone thinks you are a weirdo and makes them distant to you. But she is one of the only people who can help those who passed from life get closure with their loved ones and cross over.