The Forgotten - A last Homage from your niece....

I keep collecting material for my work "The Forgoten Ones" about the uncared graves.. those persons who (apparently) are no longer living in anybody's else memory.. the ones who died twice. 

Cemeteries can tell a lot (and raise questions) about the human condition... of the living.

This grave caught my attention in a recent visit to a cemetery...
The "drawer grave" is in the older part of the cemetery and it is the grave of a child.
The inscription says " To our beloved and adored little one João Maria, an eternal nostalgia of your parents and your little sister"
There's a later added inscription in the top corner, and another  photograph  "Also rests here  Maria... a last homage of your niece".  I presume it is the mother of the little João Maria. 

Where is dad and the other daughter?...João Maria's sister. 

Why did have, a distante relative (a niece) to render a last homage to Maria, the mother, and care of her burial?