The Duggar family celebrated Jason Duggar's 18th birthday on April 21 and as per family tradition and beliefs, Jim Bob and Michelle Duggar's 12th child can begin courting women now that he's legally an adult.

In a post on Instagram, the Duggar family shared a photo from Jason's party. With a sweet smile for the camera, Jason held up a large homemade birthday treat with a lit up number 18 candle. The birthday celebration happened early because the Duggars will be heading to Big Sandy, Texas to attend a homeschool conference, as per the family's blog.

"You have a very bright future ahead because of your commitment to Christ and your kind way of caring for and serving others," Jason's parents wrote in the caption for his 18th birthday. "We love the great example you are for your younger brothers and sisters. We are thankful for so many wonderful memories and the exciting days to come!"

Turning 18 is a milestone for every person but it's especially significant for the Duggars because it marks the time they can start looking for their life partner and begin their own families. The Duggars regard marriage and having kids as one of their ultimate purposes in life.

The Duggar kids, however, are expected to follow strict courting and marriage rules. Instead of the modern secular version of dating, they enter into a courtship during which the couple are allowed to spend time together only with other members of the family present and must not be left alone together.

They are also expected not to rush into the physical aspects of being in a relationship until they are officially husband and wife. Viewers of "Counting On" rarely see the unmarried Duggars holding hands or kissing while in courtship.

Jason's older brothers did not immediately marry after turning 18 though. First-born Duggar son Josh married Anna Keller, with whom he has five kids, at 20 years old. Seventh son Joseph went to college first before returning home to propose to and marry Kendra Caldwell, and they are now expecting their first child together.

Josiah, the eighth Duggar child, courted Marjorie Jackson for four months before they decided not to pursue marriage. He, however, met, courted and got engaged to Lauren Swanson just this March.

Second-born Duggar son John David, the twin brother of Jana, has not yet married despite being nearly 30 years old. He confessed in an episode of "Counting On" that he's not in a rush to find a wife and said, "I don't know why they're so hung up on me finding a woman."

Meanwhile, the adult female Duggar children have also married and are raising their kids with the exception of Jana who fans are eager to see happily settled down too. Jill is married to Derick Dillard and has two sons just like sister Jessa, who is married to Ben Seewald. Jinger is married to Jeremy Vuolo and will soon give birth to their first child. Joy-Anna is married to Austin Forsyth and they recently welcomed a son as well.

The question on fans' lips now is: will Jason follow suit and enter into a courtship soon?