Sarah Palin is a grandmother

Sarah Palin has become a grandmother. According to People magazine, the failed Republican vice-presidential candidate's eldest daughter, Bristol, has given birth to a 7lb 4oz son, who has been named Tripp Easton Mitchell Johnston. Baby Tripp takes his surname from his father, Levi Johnston, an apprentice electrician and former Wasilla High School hockey player who has been dating Bristol for three years. Levi and Bristol are expected to marry in 2009.

When the news broke that Bristol (pictured left, with her mother, her brother Trig and boyfriend Levi) was pregnant - shortly after Republican presidential candidate John McCain picked the Alaska governor to be his running mate - the press leapt on the story because the couple weren't married. The news triggered international debates about teenage pregnancy, abortion and the vice-presidential vetting process. There were also rumours at the time, never substantiated, that it was Bristol, and not her mother Sarah, who had given birth to the governor’s Down Syndrome baby Trig, then four months old.

The choice of the name Tripp is in keeping with the Palin family tradition of giving their children eccentric names. Bristol’s brothers are called Track and Trig, and her sisters are Willow and Piper.

"We think it's wonderful," said Colleen Jones, Bristol's aunt, who confirmed the news. "The baby is fine and Bristol is doing well. Everyone is excited." Levi Johnston's mother, Sherry, 42, has yet to comment on the news, but then she has other matters on her mind. Earlier this month she was arrested on drug charges.