In Mary Shelley's Frankenstein, there is a moment in the book where in a fit to attempt to force its creator to make it a female companion, the monster tells Frankenstein,
‘It is true, we shall be monsters, cut off from all the world; but on that account we shall be more attached to one another.’ (Chapter 17, pg. 1)
I've thought a lot about this quote since creating Meryl- so much about Frankenstein's monster revolves around isolation and being the only creature of its kind. The sentence 'but on that account we shall be more attached to one another' is an important one that relates back to the plot between Meryl and the Postwoman: while Meryl is isolated, the person that they do come into contact with- if only for a brief moment when the Postwoman delivers some mail- she immediately becomes someone that Meryl is fascinated by.
As somebody who has always been interested in Gothic literature, the monsters that I have read about are often victims of this isolation, especially if it is something that physically sets them apart from the rest of society. Frankenstein's monster is a famous example and critics have said that the monster's lack of community is what eventually drives it to the acts of killing that it does, saying that the assaults committed by the people around the monster 'translate to assaults on its identity' (Bernatchez, pg. 207).
A modern iteration of the Frankenstein story is Geek Love by Katherine Dunn, a story about a family whose parents disfigure their children in an attempt to create a circus act. The idea of community and loneliness are at play here as well- here, the two siblings Arty and Oly have to different reactions to their social isolation. Arty starts a cult that revolves around creating people like him (which involves people removing their limbs), while Oly attempts to survive in the 'real' world and look out for her daughter, for whom she wishes a normal life. Oly distances herself from the monstrous other.
The lonely monster narrative is a common one, and in my research I've seen that the monster often is led to hateful acts, especially in Gothic literature. Films can act similar to this as well, but I am familiar with many films that subvert this idea, from Shape of Water to Monsters Inc.
What I want for Meryl is to join this wave of monsters that may have a narrative revolving around lonely isolation, but that does not make them evil. Instead, Meryl will change the narrative by reaching out and finding a friend.