Does Greene present Phuong as an object or a character?

The reader learns about Phuong primarily through Fowler, the protagonist of The Quiet American, and Fowler's description of her is limited and superficial, though they are lovers. She appears to have a quiet personality, and she seems to enjoy a passive existence, but Fowler's depiction of Phuong may or may not accurately represent her.
With this observation in mind, a reader of Greene's The Quiet American could argue that Phuong is more object than woman, but that may be Fowler's fault more than Phuong's. Greene's presentation of Phuong through the lens of Fowler means that Phuong's role is ambiguous, so whether Phuong is object or character may depend on how the reader perceives Fowler.
For example, Phuong's need for stability does not receive close examination by Fowler, who even tells Pyle that he has no real investment nor interest in Phuong's experience of their relationship; this lack of engagement allows Pyle to feel justified in his desire to marry Phuong, especially as Fowler is still legally married and cannot marry her himself. Fowler treats Phuong like an object, but Pyle doesn't; Greene offers the reader a similar choice.