你們很幸運。

You're in luck.

You're fortunate.

You are in luck.

Source: Tatoeba

Sentence Composition

1 你們 nǐmen you (plural)
2 很 hěn
  1. very; quite
  2. (also, often used before an adjective without intensifying its meaning, i.e. as a meaningless syntactic element)
3 幸運 xìngyùn
  1. fortunate; lucky
  2. good fortune; luck