Through her marriage to Branicki she became administrator of the immense estate of Biała Cerkiew (today Bila Tserkva, Kyiv Oblast, Ukraine).

[3] According to an alternative account, she was Catherine's daughter by Count Sergey Saltykov and that on learning of her arrival, tsarina Elizabeth had her swiftly substituted for a handy male neonate of Estonian parentage, who eventually grew up to be Tsar Paul, Catherine's son and heir.

They arrived as uneducated and ignorant, but Alexandra was soon given a sophisticated polish and made to be the most favoured woman at the Russian court.

[6] The British ambassador, Harris wrote about her in terms of, "a young, very attractive and well-shaped lady, with a superior talent for creating plots", who spent a great deal of time with Catherine and Potemkin and that: "unless her uncle changed his attitude toward her, she is likely to become the next female confidante" of Catherine.

[6] After her marriage, she could no longer keep her position as maid of honour, which was reserved for unmarried women, but was promoted to the rank of lady-in-waiting, and thus was able to continue to attend court.

While her spouse lacked any sense of financial restraint and frequently amassed huge and ruinous debts, these were never a problem, since Alexandra was by contrast a shrewd businesswoman.

The enormous estate of Alexandria Palace and park, outside Bila Tserkva, was designed as the epitome of Polish classicism and named after her by her husband, Franciszek.

Likewise, for many years, there were rumours in Poland that Potemkin had plans to make her children heirs to the Polish throne.

In 1816, Wiegel reported how she was kissed on the hand and treated with the same deference as an imperial grand duchess, and that both she and the court seemed to take this for granted.