Marcia’s origin: “Marcia Blythe’s dear love”

Hi creepy. You know the drill. Happy revmo

This is a short piece so I don't have a ton to say, but I do have some. You use "who" twice in back-to-back phrases. I think switching one of them would feel less clunky.
I like the tone of this. A bit annoyed, a bit comedic but on the wry side like after you laugh at a crazy experience.

Their parents didn’t see the problem in Luna Rosa talking about ghosts, probably because they weren’t the ones being bothered by her

Felt.

I do wish there was a little bit of an explanation on how the supernatural came crashing into her life since its made to be a very literal interpretation. I dont even think a huge explanation is in order, but maybe just a brief sentence about whatever we creature did appear before her.

~Messy

Heya vampricone! It may not be our favorite spooky season yet, but that doesn't mean that NovemberCrow can't stop by and leave a quick review on your story!

Once, there was a sixteen year old girl named Marcia Blythe, who had a fourteen year old sister named Luna Rosa who absolutely loved to talk about “ghosts being real” and how she wanted to “communicate with ghosts one day”.

I like how you make Marcia's attitude towards Luna Rosa's ghosts clear to us from the very beginning - whenever she talks about ghosts and related matters, thanks to the quotes, I can perfectly imagine the ironic tone of an older sister who is annoyed by her younger sibling with something that Marcia is not interested in at all and considers nonsense. Some siblings are obsessed with Minecraft, some with ghosts, so I guess that every sibling duo has their own thing
I highlighted this entire paragraph because I also wanted to leave some criticism. It's not a big deal, but I feel like the first sentence sounds a little...dry? We introduce both characters at once, in the style of "This is (x-years-old) girl named meno." Maybe you could try rewriting it like this:

Once, there was a sixteen year old girl named Marcia Blythe, who had a two years younger sister named Luna Rosa

Or maybe you could try splitting that sentence up and adding a little more detail that separates the characters a bit in a different way like "Luna is the one who likes ghosts and Marcia is the one who doesn't." Well, that's just something I might prefer to see there, so feel free to take as much of it as you want!

But, unfortunately for Marcia, she’d run into the supernatural one day.

This sentence almost sounds like a harbinger of some great disaster and fills the reader with a combination of anxiety and curiosity. In the rest of the story, you give us only minimal details, which only increases the tension!

Her poor heart would twist with horror and despair, along with a sense of deep, undeniable love. Why, she’d grow to miss the days of Luna Rosa’s talk of ghosts!

If I had to pick a sentence that I would mark as the highlight of this work, it would be this one! When I first started reading this sentence, I expected it to go into the classic cliché about Marcia falling in love - but no, in fact, this entire sentence is about the pain that love can cause us, about love between siblings!

Such are the woes of having siblings, never realizing how lovely they are until that opportunity to be with them is gone.

This part really piqued my interest in finding out how things turned out for the pair of sisters in the end!

It’s such an odd thing, isn’t it?

What better ending than a question without a clear answer?

Have a nice rest of day/night and stay safe!

- Kay