According to Jacob Botoshansky, after the outbreak of the first World War, K. participated in her revue theatre in Bucharest.

It was noted about her:

"A Yiddish girl who came to the theatre as a chorus singer and later became the soubrette of the troupe. Anya Kapustin in time became a known Romanian operetta actress, not so because of her talent, but because of her beauty, and the anti-Semitism had created a scandal and the [aropgeshlept] of the stage. The actresses [in the revue-theatre] were their [eyferzikhtik] on the local chorus, and Madame Berger, who then was a woman in the [fertsiker, hot duka gevolt] acted her role for an eighteen-year-old young lady.... Yankl [Botoshansky] had for the first time hard of the timeless song of the old actresses: ["Ir zent foarlibt in ir, git ir ir roln"...Also the [diklekhe kurtse] prima donna Leahkele Kreyzlere was [turiadik oyferzikhtik] on the [elonter] Kapustin, and she [geshit pekh un shvebl] in the [igeynerish-yidish shprakh fufn her man"].

Jacob Botashansky -- "Di lebnsgeshikhte fun a idishn zhurnalist", Buenos Aires, 1942, p. 250.