In line with the trope, Bella is created so that she can be easy to control and impress, while also being imbued with sexuality on account of her adult body. But the men around her never get to attain the things they created her for because, from the outset, Bella cannot be controlled.
We get the first hint of this when Max McCandles, Godwin Baxter’s apprentice, admires Bella’s beauty only for her to urinate all over herself and the floor at the same moment. She’s desirable and undesirable at the same time. She doesn’t have the vocabulary to engage in meaningful conversations, and she takes things literally because she doesn’t understand social nuances yet, which is also why she blurts out inappropriate thoughts at inappropriate times. So while she’s beautiful to look at, her growing mind and the independent will it inevitably instills in her create an enormous barrier between the men in her life and what they want to use her for.
Lawyer Duncan Wedderburn is literally driven insane by his inability to contain Bella. He first meets her after Godwin has arranged for Max to marry Bella—without her consent, naturally—and hires Duncan to essentially keep Bella legally captive in the marriage. After Duncan and Bella meet, she tells Godwin she’ll agree to the marriage, but she first has to sow her wild oats with Duncan on a pan-European voyage.
Duncan’s agenda on the trip is transparent—he’ll use Bella until he gets bored, and then he’ll surely move on. What he doesn’t bank on is that Bella has an agenda of her own, and it’s not entirely compatible with his. She wants to learn about the world and see things past her backyard. But because she doesn’t understand how the adult world works, she doesn’t get that satisfying her sexual appetite with anyone other than Duncan might hurt his feelings, or at least break a few rules in their relationship, which, in fairness to her, she’s unaware of. What’s interesting is that in many ways, she’s behaving like Duncan would—he just didn’t expect it to be done to him.
Predictably, Duncan reacts to Bella’s transgression by trying to isolate her on a cruise ship. But things only get worse for him when a fellow passenger gives Bella books to read. As she broadens her intellect, she realizes how dull Duncan is, and she’s willing to tell him that to his face.
Over the course of his brief relationship with Bella, Duncan’s demeanor shifts from commanding and confident to feeble and inept. At the same time, his undoing is completely his fault. He never really listened to Bella or asked her to expand on the weird things she’d say that he didn’t understand. She was merely a sexual conquest for him, but because he never took an interest in who she was, he was unprepared for who she turned out to be.