彼女は私より5歳年下です。
tbd
She's five years younger than me.
She's five years younger than I am.
她比我小五岁。
She is five years junior to me.
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