Take a story's temperature by studying its tone. Is it hopeful? Cynical? Snarky? Playful?
Sympathetic, Serious
Since the story is told largely from Connie's point of view, it's generally sympathetic toward her as it explores her thoughts and feelings. Even when criticizing how superficial her romantic notions are, you get the sense that the narrator maintains a kind of affection for Connie. (This reminds us a little of the tone of Jane Austen's Emma).
The tone of those vivid and sensuous descriptions of Connie as she daydreams, for example, is in marked contrast to the dismissive tone her mother takes toward her fantasies. The tone gets increasingly serious as the threat of violence escalates in Connie's encounter with Arnold Friend.