Isabella Linton and Edgar Linton's sibling relationship

Isabella Linton and Edgar Linton, the two children of the Linton family of Thrushcross Grange, begin their story as the closest of kin, bound by affection and a shared, sheltered upbringing. Edgar, the elder, loves his sister tenderly, a devotion that is put to its severest test when Isabella develops a sudden and irresistible attraction to Heathcliff, the tolerated guest at Wuthering Heights. At eighteen, Isabella is described as a charming young lady, infantile in manners, yet possessed of keen wit, keen feelings, and a keen temper. Her brother, who comprehends Heathcliff's unchangeable and unchanged mind, is appalled by this fantastic preference, dreading the idea of committing his sister to the keeping of a man whose very disposition revolts him. He is also acutely aware of the practical dangers: the degradation of an alliance with a nameless man, and the possibility that his property, in default of heirs male, might pass into such a one's power. Edgar's opposition is not born of mere snobbery but of a clear-sighted understanding of Heathcliff's character, a perception that Isabella, blinded by her infatuation, utterly lacks. He would have recoiled still more had he known that her attachment rose unsolicited and was bestowed where it awakened no reciprocation of sentiment, for he laid the blame for her feelings squarely on Heathcliff's deliberate designing.