TLC has their preview description up of the next Little People, Big World special on June 10th at 8pm.
This one is called "Amy's 50th" (note that factually, Amy's birthday is Sept 17th).
Jun 10, 8:00 pm
Little People, Big World: Amy's 50th
The confluence of Amy's 50th birthday and Matt and Amy's 25th wedding anniversary inspires Matt to take Amy on an adventurous and romantic road trip to California. The couple re-trace their honeymoon steps in San Francisco and Matt surprises Amy.