overplay (one's) hand

Translations
переоценить (свои) возможности
She overplayed her hand by demanding a higher salary, and now she might lose the job offer.
Она переоценила свои возможности, требуя повышения зарплаты, и теперь может потерять предложение о работе.
Definitions
To overestimate one's own position, power, or advantage in a situation and act too aggressively or confidently, often resulting in a loss or setback.