By keeping it secret, Maria Petrovna was protecting her daughter from trouble at the times when any relation to a 'traitor' could lead to prosecution.
Among her other lauded performances were those of Lolya (Dion), Knipper-Chekhova (My Whimsical Happiness), Nicol (Le Bourgeois gentilhomme), Maria (The Cavalry Army, after Babel) and Mamayeva (Enough Stupidity in Every Wise Man).
[1] Among other critically acclaimed films she appeared in later, were Old Russian Vaudevilles' Evening (1979, where she played five different women), Igor Talankin's drama Father Sergius (after Leo Tolstoy's short story) and Die Fledermaus, Ian Frid's musical film after Johann Strauss Strauss' classic, alongside Yuri and Vitaly Solomin.
Much lauded were her Anna Karenina in Roman Viktyuk's 1983 production (based on Mikhail Roshchin's remake of Leo Tolstoy's novel), Paola in The Lady Without Camellias (after Terence Rattigan's play), Bizyukina in Soboryane (based on Leskov's novel) and Louise in I Don't Know You From Now On, Dear (after Aldo De Benedetti's play).
[1] Lyudmila Maksakova's first husband was the artist Lev Zbarsky (who in 1972 departed to Israel, then to the USA); they had a son, Maxim.