The ever-growing Duggar family of TLC's "19 Kids and Counting" has a lot to celebrate this week.

The brood welcomed a new son-in-law, celebrated a daughter-in-law's birthday, and commemorated their oldest child's engagement anniversary.

On June 23, the family celebrated daughter-in-law Anna Duggar's 26^th birthday. Anna is married to Jim Bob and Michelle's oldest child, Josh, and they have three children: Mackynzie, 4, Michael, 3, and Marcus, 1. The couple was also celebrating Anna and Josh's anniversary.

Josh proposed on June 23, 2008, and they were married three months later. Josh, 26, shared an Instagram photo on Monday expressing his love for his family.

"Happy birthday (& our 6-year engagement anniversary!) to my beautiful wife @annaduggar! Glad to spend it w/ David & Priscilla!" he wrote in the Instagram caption. David and Priscilla Waller are Josh's brother- and sister-in-law.

Anna also shared a photo of Josh on one knee, proposing marriage, six years ago.

On June 21, 23-year-old Jill became the first Duggar daughter to get married. She wed 25-year-old Derrick Dillard in front of over 1,000 guests at Cross Church in Springdale, Arkansas. The couple began courting in November, and were engaged by April.

Jill said they knew almost immediately after meeting that they would marry.

"When we finally met in person in Nepal, we knew within days that we wanted to spend the rest of our lives together," she told ABC News after the engagement.

Last week, Michelle Duggar shared words of wisdom for Jill and other newlyweds.

"Be available," she wrote in a TLC blog post, sharing advice that a friend told her before her wedding to Jim Bob in 1984.

"'You are the only one who can meet that special need that he has in his life for intimacy... And so be available, and not just available, but be joyfully available for him.'

"Talk about disagreements privately...We always say in our family, we praise publicly, but we correct privately. And that's marriage advice that I would give to anyone.

"Get marriage advice when you need it," she advised. "There are going to be those times in your marriage where you might not always agree...

"Yes, we have a oneness with spirit in Christ, but there are times that we need others to give us life counsel. So be willing to go seek it together."