The pair "are turning a new page" to co-parent their son Tripp

Credit: Celebrity Photo; Wenn

Bristol Palin and former fiancé Levi Johnston are getting past their differences – and their public custody fight – to start what she calls “a new page” in their lives as parents.

“I am doing my best to raise a happy, active and healthy boy. I believe that wherever possible, if the parents can cooperate and co-parent in a positive way, the child will benefit,” the mom of 17-month-old Tripp tells Good Morning America.

“Levi and I are turning a new page here as co-parents to this wonderful boy,” adds the 19-year-old, “and putting aside the past because doing so is in Tripp’s best interest.”

The new level of cooperation comes more than a year after Palin and Johnston, 20, split and called off their engagement.

Last month Palin, who has become a spokesperson for teen abstinence, called Johnston “a stranger to me,” telling Harper’s Bazaar that she ignored his public behavior, which included posing for Playgirl and going to Los Angeles to become an aspiring model and actor.

But the daughter of former vice presidential candidate Sarah Palin has been vocal about having Johnston be part of Tripp’s life. She told The Today Show‘s Matt Lauer last year that she wanted Johnston to be involved with their son.