Ekaterina was the only child of Andrei Ushakov [ru] from his second marriage to Elena Leontyeva Apraksina, née Kokoshkina.

[3] Ernst Johann von Biron wanted to use Ekaterina's relationship with the Grand Duchess to disrupt her proposed marriage to Duke Anthony Ulrich of Brunswick and instead marry her to his son Peter.

The bride was escorted to the church by Tsarevna Elizaveta Petrovna and Grand Duchess Anna Leopoldovna.

They settled in Saint Petersburg in 16 Dvortsovaya Embankment, which Ekaterina Andreevna inherited after her father's death in 1747.

[6] Ekaterina Andreevna died on 25 September 1779 from a stroke and was buried in the Lazarevskoye Cemetery of the Alexander Nevsky Lavra.