Losing the borrowed necklace ruined the Loisels completely. To replace it, they borrowed thirty-six thousand francs and spent ten years repaying the debt. They gave up their maid, moved to an attic, and worked tirelessly. Matilda did rough household chores while her husband worked day and night, aging them both beyond their years.
Examiners expect you to cover two aspects: (1) the immediate consequence — borrowing a huge sum to replace the necklace, and (2) the long-term consequence — ten years of poverty, hard labour, and loss of youth/beauty. Since it is 2 marks, one point each is sufficient. Avoid retelling the whole story; focus on the change in their life. The irony (the original necklace was fake, worth only 500 francs) is not required here unless the question asks for it.