Answer:
Cada año los miembros de mi familia vuelan a Nueva York. Nosotros nos reunimos para celebrar el cumpleaños de mi abuela.
Explanation:
In Spanish, reciprocal verbs are those that express actions that two or more people do to each other, or that two or more people do together. They are formed with a plural personal pronoun + its appropriate reflexive pronoun + the verb conjugated. Here's an example of how the reciprocal verb “reunirse” (to meet/to gather) is formed (notice that only plural pronouns are used to create this type of verb):
Personal Pronoun / Reflexive Pronoun / Verb
Ustedes, Ellos, Ellas / se / reúnen
Nosotros / nos / reunimos
Vosotros / os / reunís
The sentence then should be completed with “nos reunimos,” which it's the appropriate reflexive pronoun and verb for the personal pronoun “Nosotros.”
