John Luke Robertson and Mary Kate McEacharn to hold wedding in June 2015

John Luke Robertson and Mary Kate McEacharn(Photo: Instagram/John Luke Robertson)

Engaged teenager Mary Kate McEacharn wrote a touching blog post on how she found love with her fiancé, John Luke Robertson, and insisted that they are not too young to marry.

John Luke is the son of "Duck Dynasty" stars Willie and Korie Robertson, and is 19 years old.

McEacharn, 18, became engaged on October 11 – John Luke's birthday. She detailed the surprise proposal on her fiancé's "Young and Beardless" blog.

"I arrived early at his home so we could ride together to his party and also so he could open his presents from me," she explained on Monday. "Sitting on the table was a photo album he had made completely full of pictures of us... from when we first met at King's Camp to the previous weekend when we went to a festival in Austin.

"I finally came to the last page as he leaned over to 'put his shoes on.' There was a handwritten note stuck on the page and as I read it, it finally struck me what was going on.

"(John Luke actually found a ring I had pinned on pinterest and took it to his cousin who is a jewelry-maker...together they went by that and designed a one-of-a-kind ring).

"I looked up to find him on one knee, holding the ring out, and he said 'Mary Kate McEacharn, will you marry me?' Despite my shock, I managed to say yes...and then say it again about twenty more times to get my point across!"

The couple was joined by their friends and family for an unforgettable celebration.

While the Robertson and McEacharn families are joyous about the union, the couple has been criticised online for deciding to marry at a young age. McEacharn said that she and John Luke will "grow up" together.

"With God as our leader, we know that we can make it," she wrote. "A lasting marriage doesn't depend on your age, it depends on your love for God and your love for each other, and your willingness to make it work.

"I honestly could not be more excited to spend the rest of my life with John Luke Robertson."

The blog ended by confirming that they will tie the knot in June 2015 but did not give an exact date.

"Being engaged has been awesome and we are counting down the days until the wedding in June," she said.