Final answer:
Elizabeth decides to share with Jane the fact of Darcy's proposal but conceals his negative remarks about their family and any mention of his involvement in Jane's romantic separation from Mr. Bingley, out of consideration for Jane's feelings.
Step-by-step explanation:
When Elizabeth Bennet resolves to inform her sister Jane about Mr. Darcy's initial marriage proposal, she chooses to withhold certain details to protect her sister's feelings and to keep some troubles to herself. Elizabeth desires to be honest with Jane, but she also recognizes the need to be selective with information to avoid unnecessary hurt or scandal. While she discloses the fact that Darcy has proposed, she omits the particulars of his disparaging remarks about their family and possibly his role in separating Jane from Mr. Bingley. This decision reflects Elizabeth's tactfulness and consideration for her sister's well-being.