As such, Richardson proved a fine and capable stage player, bringing charm and a surprising vocal command to the singing role of Tracy Lord in a West End staging of "High Society" (1986), alongside Stephen Rea. She made her NYC debut reprising the role of "Anna Christie", picking up several accolades, including a Tony nomination, and later marrying her co-star Liam Neeson. In 1998, after a respite to give birth to two sons, she returned to work as Sally Bowles in an environmental staging of "Cabaret". Critics were rapturous in their praise for Richardson who managed to obliterate memories of Liza Minnelli's film performance. Once again, she earned a Tony nomination for her work.

In her film and TV work, the swan-necked, smoky-voiced champagne blonde actress often was cast in roles that combine a seductiveness with nervous, even neurotic, emotional tension. Just as he had guided Vanessa Redgrave in "The Devils" (1971), Ken Russell cast Richardson in the role of Mary Godwin in "Gothic" (1987), which she invested with calm and sanity in light of the overblown horrors around her. She was appropriately sensual as a vicar's wife in Pat O'Connor's underrated "A Month in the Country" (also 1987) and offered a stunning portrayal of heiress-turned-terrorist "Patty Hearst" (1988) in Paul Schrader's biopic. "The Comfort of Strangers" (1990) cast her as half of a torpid pair of tourists whose lives and persons are violated during a stay at a stranger's Italian villa. On the small screen, she excelled in two 1993 portraits of emotionally unstable Southern women: Catharine Holly in the remake of Tennessee Williams' "Suddenly, Last Summer" (PBS) and as "Zelda" (TNT), the mentally ill wife of American author F Scott Fitzgerald. More recently, she teamed onscreen with husband Neeson as doctors examining a "wild child" (Jodie Foster) in "Nell" (1994) and was the ex-wife of Dennis Quaid whom their twin daughters try to reunite in the remake of Disney's "The Parent Trap" (1998). As she has come in to her own as a person and a performer, Richardson now seems ready to tackle working again with members of her famous family.

In 2001, Richardson starred in the Emmy-nominated TV Movie "Haven" as Ruth Gruber, an American woman who helped save the lives of 1000 Jews in Europe during WWII. She also had a role in "Chelsea Walls," a somber, experimental film directed by Ethan Hawke. In 2002, Richardson had a featured role in the comedy "Waking Up in Reno" about two couples who travel to Reno for a monster truck convention, and was particularly noticeable as an obnoxious blue-blooded New York socialite in the Jennifer Lopez vehicle, "Maid in Manhattan." Richardson then served as executive producer, as well as lead actress, for the dour period drama, “Asylum” (2005). She played a bored 1950’s housewife who falls in love with an asylum patient (Marton Csokas) under the care of her husband (Hugh Bonneville), the hospital’s forensic psychologist.