You're right, Jelena- several online sources had 'Helen Kirwan-Taylor' mention her son Constantin; a Times source shows a Charles Kirwan-Taylor to be married to Helen-
https://www.thetimes.co.uk/article/big-shot-charles-kirwan-taylor-kl0hzw90hpk - also a 2006 issue of 'Deal Pipeline' says of Charles Kirwan-Taylor "The British Kirwan-Taylor is married to Helen Kirwan-Taylor, an American jourmalist who writes about lifestyle issues". This Charles Kirwan-Taylor is Charles Patrick Kirwan-Taylor, as you identified, son of Julia (née Ogden) by her first husband, Peter Robin Kirwan-Taylor (1930-), of Bridgehampton, Suffolk County, N.Y., U.S.A., 2nd Lt Rifle Brigade etc. (per BP 2003). A 1988 marriage record for Charles P. Kirwan-Taylor gives wife as Helen v[on Thiesenhausen] Semler, dau. of Peter Semler, of New York and Paris, a diplomat consul general, U.S. Consulate, Milan 1990-, political minister, American Embassy, Paris 1986-9, counselor, American Embassy, Rome 1982-6, counselor, American Embassy, Moscow 1979-82, political advisor, U.S. Mission, West Berlin 1974-9, office chief, Arms Control Agency, Washington 1972-4, foreign service officer Russian desk, Department of State, Washington 1970-2, 2nd secretary, American Embassy, Paris 1967-70), and Elena Konstantinova ('Helen'; 1933-2001), a Russian translator for the White House and State Department, dau. of Konstantin Boldyreff, head of the Russian department, Georgetown University, son of Lt-Gen. Vasilii Georgevitch Bolydreff, commander-in-chief of the White Russian forces during the Bolshevik Revolution (see also
https://www.nytimes.com/1988/11/27/style/paris-wedding-for-miss-semler.html and
https://www.washingtonpost.com/archive/local/2001/01/16/helen-semler-dies/fc657c71-0e10-4949-b134-68c63c7b93db/?noredirect=on); Constantin Christopher Kirwan-Taylor, mother 'Semler' b. 1994 (brother Ivan Dominic b. 1995).