(26 August 1992 - 29 October 1999) (his death)
In 1982, Lyngstad left Sweden and moved to London. In 1986, she relocated to Switzerland, and lived with her boyfriend, architect Prince Heinrich Ruzzo Reuss of Plauen (1950–1999) in his family castle in Fribourg.
In 1988, Lyngstad became a grandmother when her daughter, Ann Lise-Lotte, gave birth to a son named Jonathan.
On 26 August 1992, Lyngstad married Prince Reuss. By this marriage, she has two stepdaughters, the twins Princess Henriette Reuss and Princess Pauline Reuss (both born 2 June 1977, Oslo, Norway).
Through her marriage to Prince Reuss, who had been a student at the same boarding school as Crown Prince Carl Gustaf – who later became the King of Sweden – Lyngstad became acquainted with the Swedish royal family and eventually became close friends with Sweden's Queen Silvia.
On 13 January 1998, Lyngstad's daughter, Ann Lise-Lotte Casper (née Fredriksson), died of injuries sustained in a car accident in Livonia, New York – a town 20 miles south of Rochester, New York.
The prince died of lymphoma in October 1999.