stiffen up (someone's) upper lip

Translations
держать удар
Despite the bad news, she managed to stiffen up her upper lip and carry on.
Несмотря на плохие новости, она смогла держать удар и продолжить.
Definitions
To encourage someone to remain brave, stoic, or unemotional in the face of difficulty or adversity; to urge someone to control their emotions and not show distress.