The Alaska governor's daughter and boyfriend Levi Johnston are proud parents.

Bristol Palin, the 18-year-old daughter of former Republican vice-presidential candidate Sarah Palin, gave birth on Sunday to a healthy 7 lb., 4 oz., baby boy in Palmer, Alaska, PEOPLE reports.

"We think it's wonderful," said Colleen Jones, the sister of Bristol's grandmother Sally Heath, who confirmed the news. "The baby is fine and Bristol is doing well. Everyone is excited."

The baby's name is Tripp Easton Mitchell Johnston, according to Jones.

Baby Tripp takes his surname from his dad, Levi Johnston, an apprentice electrician and former Wasilla High School hockey player who has been dating Bristol for three years. 

Bristol Palin is currently residing in Wasilla and completing her high-school diploma through correspondence courses.

Johnston is studying to become an electrician. He told the Associated Press in October that he and fiance Bristol plan to wed in 2009 and raise the child together.

Bristol, the eldest of Sarah and Todd Palin's three daughters (the couple also have two sons), made headlines with her pregnancy last summer, shortly after Republican presidential candidate John McCain picked the Alaska governor to be his running mate on his party's ticket.

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In a statement at the time, Bristol's parents said their daughter "came to us with news that we as parents knew would make her grow up faster than we had ever planned." They added, Bristol "has our unconditional love and support."

This week, Levi Johnston's mother, Sherry Johnston, with six felony counts of misconduct involving a controlled substance, described by an Alaska State Troopers spokeswoman as being Oxycontin. Johnston's arraignment is set for Jan. 6.