What is Akimi's mother?

Finally got around to reading a book favored by many of my students.  So far, the writing is crisp and fluid, the storyline is intriguing, and the main character is easy to like. Then, I ran into a sentence that caught me by surprise: “Akimi’s mother is Asian, her dad Irish.”  I tried to imagine why the narrator decided to name the COUNTRY of origin of this character’s father — IRELAND, and to name the CONTINENT of origin of this character’s mother?  The symmetry would have been, “Akimi’s mother is Asian, her dad European,” or “Akimi’s mother is Japanese, her dad Irish.”  (Akimi is a unisex Japanese name.)

By naming the father’s specific country, we acknowledge that different European countries have different cultures and traditions and also different background/immigrant stories.  By naming the mother’s origin as from one generic and vast continent, we erase the differences of the diverse cultures and heritages, and fail to acknowledge the different background/immigrant stories.

Of course, one cannot know what went into writing and editing such sentences: I don’t know whether the author originally put in the ethnicity of the mother and was advised to change it; I don’t know whether there are reasons I am unaware of that naming the mother’s heritage might be offensive; I don’t know that it is not just so common a narrative convention that no one on the editorial team would be able to catch the inconsistency and correct it.  

Few people would even notice this unessential sentence unless they are like me who reads statements like this and see the bright neon sign of frustration: when will American, non-Asian writers start realizing that Asians and Asian Americans belong to many different sub-groups, all carrying with them drastically diverse beliefs, traditions, and histories? And if they’d like to put in some ASIAN characters to “diversify” their stories, perhaps some more understanding of where those characters came from, what kind of back stories they and their forefathers might have would have helped to raise the authenticity meter? And also perhaps consider: whether they behave more like those from their countries of origin or more like your “common” Americans… (by the way, what IS a “common” American?)