Miànduì zhìyí, tā shǐzhōng méiyǒu luàn le zhènjiǎo, chénzhuó yìngduì.
Faced with questioning, she never lost her composure and responded calmly.
Tips
usage
阵脚 is almost always used in the set phrase 乱了阵脚 (to lose one's footing / to be thrown into disarray). It originally referred to the flank of a military formation but is now used figuratively for losing composure or strategic footing.