This is a polite way to ask is Amnon has had sexual relations with her. Alternate translation: "Has Amnon your brother slept with you?" (See: [[rc://en/ta/man/jit/figs-euphemism]])
The phrase "take something to heart" means "to worry about it." Alternate translation: "Do not worry about what has happened" (See: [[rc://en/ta/man/jit/figs-idiom]])