Ekaterina Nikolaevna was the daughter of pomeshchik, guard ensign Nikolai Petrovich Poltavtsev (1769–1849) and Daria Alexeevna Pashkova (1798–1842), owner of the Pashkov House.

Ekaterina Nikolaevn graduated from the institute in 1839[8] and on 15 March of the same year, she was accepted as a maid of honour to the court of Grand Duchess Maria Nikolaevna.

[10] As a member of the intimate circle of Alexander II, on the occasion of his 25th wedding anniversary, Countess Adlerberg was made a dame of the Order of Saint Catherine (lesser cross), and on 22 July of the same year, her daughter, Maria, was granted the position of maid of honour.

Having lost her position at court, Countess Ekaterina Nikolaevna openly expressed her dissatisfaction and made comments about the ingratitude of the sovereign.

When her nephew, General Mikhail Skobelev was recalled to Saint Petersburg after his Paris speech, the Countess defiantly arrived to meet him at the station with a huge bouquet of flowers, which further alienated society.

According to one of the friends of Alexander III (Illarion Vorontsov-Dashkov), Countes Adlerberg 'kept 450 thousand rubles in the cash register of the Ministry of the Court and made a fortune for herself from various kinds of dark scams'.

[13] After leaving the court, Ekaterina Nikolaevna settled in Tsarskoye Selo, where she died of pneumonia on 3 June 1910.