Answer:
<u>A big</u> day in the life of a young Latina woman is her quinceañera, or fifteenth birthday.
Both revisions are acceptable.
Explanation:
Big = large, significant, special.
<u>A big</u> day ... can be revised with "A <u>special</u> day ..." and / or "A <u>significant </u>day ..." and any of the the following listed synonyms. It is the context that defines which word is most appropriate.
The synonyms of significant include the following, depending on context: serious, crucial, weighty, material, appreciable, momentous, of moment, memorable, unforgettable, pronounced, marked, considerable, obvious, conspicuous, striking, glaring, signal, impressive, uncommon, unusual, rare, extraordinary, exceptional, particular, special.