有男颜的女生最幸福
[yŏu nán yán de nǚ shēng zuì xìng fú]
It means 'A girl who has her man's appearance is the happiest.' It reflects an idea or hope that having a beloved partner makes one the happiest. Note, the literal meaning could be slightly misleading as it doesn't mean 'a beautiful boyish-faced girl is happiest', but implies having someone by your side, specifically for girls