Read it through once

“Aunt Isabella had not you and me to nurse her,” I replied. “She wasn’t as happy as Master: she hadn’t as much to live for. All you need do, is to wait well on your father, and cheer him by letting him see you cheerful; and avoid giving him anxiety on any subject: mind that, Cathy! I’ll not disguise but you might kill him if you were wild and reckless, and cherished a foolish, fanciful affection for the son of a person who would be glad to have him in his grave; and allowed him to discover that you fretted over the separation he has judged it expedient to make.”