Cottrell (67) won the title at the New Zealand Masters Games in 2010 but lost it two years later.
She won a tense final this week against fellow Dunedin bowler June Pickles 10-8.
Cottrell got the better start and led 6-4 after six of the 12 ends.
But Pickles came back with a two and one on the next two ends to lead 7-6.
''I wasn't worried but I knew I had to be on my toes,'' Cottrell said.
''We had a game on and it could have been anyone's at that stage.''
Cottrell consolidated her position by scoring one, one and two on the next three ends to lead 10-7 with just one end left.
Cottrell was in the box seat but it was crisis time when she came to play her last bowl of the game.
Pickles had trailed the jack with her third bowl and had three shots on the head.
''I felt that June was getting draw bowls better than me on that end of the mat,'' Cottrell said.
''But I hadn't lost a game all day and was playing consistently.''
Cottrell remained calm and walked up to the head and examined it before playing her last bowl. It calmed her nerves.
''I find that it always pays to stop and come up and have a look at the head to see what you are dealing with and then go back and play the bowl,'' she said.
Cottrell's bowl curled in between the shot bowls to take second shot and Pickles was short with her last bowl.
''I just wanted it anywhere among her three bowls,'' Cottrell said.
''I was relieved when it happened.''
Cottrell was introduced to indoor bowls at a young age when her mother took her along to games. She was 11 when she started competitive bowls.
She played bowls until she was aged 22 but gave the game away for 25 years while she brought up seven children.
Cottrell has been back playing bowls for the past 19 years and has won eight Otago titles.
A highlight in her career came last winter when she was selected in the South Island team for the first time.
''I skipped the women's four and we won the interisland medal in Rotorua,'' she said.
She has won plenty of medals at Masters Games and other indoor bowls events.
''I used to put them on a board but it is full and I haven't got round to getting a new board,'' Cottrell said.
''The medals are just left in a draw.''
The under-61 gold medal was won by Judy Cosgrove (Christchurch) who was competing in her first Masters Games.
