Answer by taking a quote from the following article:

Sonny & Cher were an American pop music duo, actors, singers and entertainers made up of husband-and-wife Sonny and Cher Bono in the 1960s and 1970s. The couple started their career in the mid-1960s as R&B backing singers for record producer Phil Spector. The pair first achieved fame with two hit songs in 1965, "Baby Don't Go" and "I Got You Babe". Signing with Atco/Atlantic Records, they released three studio albums in the late 1960s, as well as the soundtrack recordings for two unsuccessful movies, Good Times and Chastity, with Cher contributing vocals to one cut, "Chastity's Song (Band of Thieves)" .

On January 5, 1998, Bono died of injuries from hitting a tree while skiing at Heavenly Ski Resort in Lake Tahoe. He was 62 years old. Bono's death came just days after Michael Kennedy died in a similar accident. Bono's widow, Mary, was selected to fill the remainder of his congressional term, and was re-elected in her own right, serving until 2013. She continues to champion many of her late husband's causes, including the ongoing fight as how to best save the Salton Sea.  The funeral, unbeknownst to Cher, was broadcast live on CNN. She gave a tearful eulogy, after which the attendees sang the song "The Beat Goes On". In front of millions, Cher tearfully and effusively praised Bono, calling him "the most unforgettable character I've ever met". His final resting place is Desert Memorial Park in nearby Cathedral City, California, the same cemetery in which Frank Sinatra was laid to rest later that same year. The epitaph on Bono's headstone reads: "And The Beat Goes On".  In 1998, Sonny and Cher received a star on the Hollywood Walk of Fame for Television. Cher appeared at the event with Mary Bono, who accepted the award on behalf of her late husband. Cher paid tribute to Bono in the CBS special Sonny and Me: Cher Remembers, calling her grief "something I never plan to get over". During the same year, Cher also released her twenty-second album Believe that was highly influenced by Bono's death, and in the booklet Cher wrote "In memory of Son".  When Cher and Bono divorced, they agreed to split revenue from the songs recorded together. When Bono died, one-third of his interest passed to wife Mary Bono-Mack, and one-sixth interests were split amongst his children. Cher sued UMG in 2009, claiming she and Bono's heirs were owed $5,000,000 in "hidden" royalties.

What did Cher do after Sonny died
She gave a tearful eulogy, after which the attendees sang the song "The Beat Goes On".