彼女は私より５歳年下です。
tbd
She is five years junior to me.
She's five years younger than I am.
她比我小五岁。
She's five years younger than me.
は
1. indicates sentence topic
2. indicates contrast with another option (stated or unstated)
3. adds emphasis
指示句子的主题；表示与另一选项（无论是否明确提及）形成对比；表示强调
より
1. than
2. rather than, instead of, over, above
3. from, out of, since, at, on (and after)
4. except, but, other than
5. more
更，更加