My little sister, Evie, became excited as we discussed plans for her birthday party; she laughed delightedly at my ideas, and her eyes sparkled.
"Her eyes sparkled" best completes the passage. Evie is delighted at her older sister's ideas for her birthday party and because of this her eyes sparkle. It would not make sense to say she was upset or crying, as it states before that "she laughted delightedly at my ideas." Also the phrase "her teeth chattered" is not relevant to any other part of the passage.