“What possesses people - women mainly - to write these confessionals where they reveal themselves as simply old children, self-centered and narcissistic to a fault?”
You answered your own question, bud. Pure unadulterated narcissism. LOOK AT ME! To a large part of society, negative attention is better than no attention.
My take is that she is young enough that she (at some level, perhaps unconscious) still thinks she will have a child.
If that doesn’t ever happen (and its looking less likely) she will, someday and one day, begin to grieve about that baby. She just doesn’t know it yet.