smooth (someone's) ruffled feathers

Translations
успокоить (чьи-то) встревоженные чувства
She managed to smooth his ruffled feathers after the argument.
Ей удалось успокоить его встревоженные чувства после ссоры.
Definitions
To calm someone down or make them less upset, especially after they have been annoyed, offended, or angered.