"We got engaged two weeks ago," 19-year-old Bristol Palin told Us Weekly. "It felt right, even though we don't have the approval of our parents."
The former Republican vice presidential candidate, who jousted publicly in a war of words with Johnston after the campaign, wished her daughter, future son-in-law and grandson the best but expressed reservations about the couple's maturity.
"As parents, we obviously want what is best for our children, but Bristol is ultimately in charge of determining what is best for her and her beautiful son," Sarah and Todd Palin said in an exclusive statement to "Good Morning America." "Bristol believes in redemption and forgiveness to a degree most of us struggle to put in practice in our daily lives."
"We pray that, as a couple, Bristol and Levi's relationship matures into one that will allow Tripp to grow up graced with two loving parents in his life," they said.
In June, Bristol Palin told "GMA" that she was reuniting with Johnston for the sake of their 1-year-old son, Tripp.
"I am doing my best to raise a happy, active and healthy boy," Palin said. "I believe that wherever possible, if the parents can cooperate and co-parent in a positive way, the child will benefit. Levi and I are turning a new page here as co-parents to this wonderful boy and putting aside the past because doing so is in Tripp's best interest."
The couple reportedly reconnected three months ago while working out a custody plan for their son.
Palin and Johnston split in March 2009 after they had appeared together throughout Sarah Palin's 2008 vice presidential campaign. The engagement signals a change of heart in something of a family feud that's been played out in headlines across the nation ever since.
Johnston, Palin Feud Played Out in Headlines
Following the breakup, the couple followed different paths. While Bristol Palin went on to be a spokeswoman for teen abstinence, Levi Johnston posed for Playgirl and is reportedly developing a reality show.
In Harper's Bazaar, Bristol said her ex-boyfriend "is a stranger to me."
"I don't want to get into it. It's just dirty laundry," she said.
Johnston has also criticized Sarah Palin, telling "Insider" that the former vice presidential candidate "doesn't do anything unless she gets something big from it."
Money woes put even more of a strain on the estranged young parents. In February, a judge ordered Johnston to pay child support and retroactive back payments estimated at more than $10,000 for Tripp's care following a lengthy court battle.
Johnston has publicly accused Palin of calling her son Trig "the retarded baby" and also said the Palins were on the verge of divorce -- accusations that Palin denied in a November interview with ABC's Barbara Walters.
"He's a kid. He's misguided," Sarah Palin said of Johnston in November. "I can't wait until he comes back on that right road of wanting to be part of the family and Tripp's life. It's going to be good."