Alexandra is believed to have been born in Moscow to Count Andrei Andreevich Tolstoy (1771–1844) and Praskovia Vasilievna (née Barykova; 1796–1879).

She was buried in a church on Konyushennaya Square in the presence of the Grand Dukes and the Empress, at the request of whom a monument was erected at the expense of the royal court.

Alexandra met Leo Tolstoy in the spring of 1857 whilst she was in Switzerland with the 'small court' of Grand Duchess Maria Nikolaevna.

When Tolstoy expressed interest in the fate of the decembrists, she directed him to Vasily Perovsky, whom she loved throughout her life.

He also utilized Alexandra's correspondence to inform his writings about life in the capital, including events at court and in the salons.

Their letters were published in 1911 by the Society of the Tolstoy Museum in St. Petersburg after the death of both addressees, as per the will of Alexandra Andreevna, who prepared the correspondence for publication.