Why does Dewey Dell hate Darl so intensely in As I Lay Dying?

Dewey Dell and Darl share a trait: both have the ability
to "talk without the words," although Darl possesses the trait more acutely than his
sister. When he sees Dewey Dell, he knows she is pregnant; she doesn't have to tell him.
Because he knows, she hates him. She fears he will tell Anse, and then what will Anse
do? Just knowing that Darl knows infuriates Dewey Dell because she doesn't trust him
with her secret, a secret she plans to do something about, although she's not exactly
sure what that will be. Having no women around from whom she can easily ask advice,
Dewey Dell is left to seek information awkwardly from the local pharmacies in the towns
the family passes through. All the while, she fears that Darl may tell someone.Her
hatred will ultimately find an odious outlet.