I just stumped reading this:
[...] Pamela, who had a fifteen year-old-son called, Ashley.
To me the comma after called looks utterly wrong, but that may be caused by German being my first language.
I would omit this comma (and the dashes):
[...] Pamela, who had a fifteen year old son called Ashley.
A comma after son would create ambiguity:
[...] Pamela, who had a fifteen year old son, called Ashley.
could mean: Pamela called Ashley (a friend).
Second problem with the original sentence is the use of dashes:
a fifteen year-old-son
There is one fact to add, the author is Australian and stated he used Australian English in his story.
HM.