so sweet!

You can definitely tell that there is some story behind this piece.

Maybe the ghost girl is her little sister. Only can wonder about how she died, maybe to unknown causes, a sickness, or some other tragic event in the life of their family.

The way she hugs her big sister could symbolize the eternal bond between siblings, which lasts even through death.

Notice how she is still wearing pajamas. This could mean that she died in her sleep, possibly relating back the the sickness speculation.