Ole Golly, Harriet could tell, was deliberately making her face bright and cheery because she didn't want Harriet to ask her what the matter was. (p. 108)(Ole Golly is the name of a character.) Everything in the sentence was fine for me until I hit the ending: "she didn't want Harriet to ask her what the matter was." On the surface, the sentence follows all the grammatical sequence of words in English nominal clauses that begin with an interrogative pronoun:
She didn't want Harriet to ask her...
what the movie was.
where the cat was.
how the book ended.
who the intruder kidnapped.The typical word order for these is INTERROGATIVE PRONOUN - NOUN PHRASE (subject) - VERB. The original sentence followed that word order:
what (IntPro) the matter (NP) was (V)So why does the sentence sound awkward to me?
It sounds awkward because of the noun phrase in the construction: the matter. It is part of an idiomized question we often use in English: What is the matter? And yet, I think it's awkward (if not ungrammatical) to use the matter in that idiom reading in a sentence: *The matter was that she left early.
So while it is entirely grammatical to say she didn't want Harriet to ask her what the matter was, it takes longer for my brain to process the sentence because it apparently doesn't like having the idiomatic the matter appearing before the verb. In a language that relies so heavily on word order, something so small as having what the matter was instead of what was the matter can make a sentence sound downright awkward.