prove (your) mettle

to show that you are brave and have a strong character.

As a reporter, she certainly proved her mettle working in the midst of a war zone.

• cry your heart out
• culture shock
• culture vulture
• cupboard love
• curate's egg
• Curiosity killed the cat.
• curl hair
• curl lip
• curl someone's hair
• curl your lip
• curry favor
• curry favor with
• curry favor with someone
• curry favour
• curtain comes down on
• curtain comes down on something
• curtain falls
• curtain falls on
• curtain falls on something
• cushion the blow
• cut above
• cut above someone
• cut above something
• cut across
• cut across something