Kate Gosselin is about to turn the big 4-0 on “Kate Plus 8.” In honor of the mom of eight’s big birthday – which occurred March 28 -- TLC is airing a two-part summer special of her family’s hit reality series.

In the upcoming installments of “Kate Plus 8,” which begin airing Tuesday on TLC, Kate and her eight children, 14-year-old twins Mady and Cara, and 11-year-old sextuplets Leah, Collin, Aaden, Joel, Alexis and Hannah, will travel to Mexico for Kate’s birthday.

Kate's sons and daughters will make their mom two different birthday cakes after arriving at their resort, as seen in a preview clip of “The BIG Four-Oh,” obtained by Entertainment Weekly.

“She’s not going to like the fact there’s a 40 on it,” Leah says. “But she can deal with it.”

The reality TV brood will also spend some time in the sun. Another scene from EW’s sneak-peek video shows the kids admiring the local wildlife, Alexis seashell hunting and Kate rocking a bikini on the shoreline.

“At this point in time, I discovered the little cabanas and let me tell you something, once I laid down, I decided that I instantly needed three more days to try out those things,” Kate says in the teaser. ”Oh, it was so comfortable. It was the relaxation I needed at the end of that busy trip.”

The first one-hour “Kate Plus 8” birthday episode airs Tuesday at 10 p.m. EDT on TLC. The second half of the special, titled "Birthday #11," premieres Wednesday, June 30, at 10 p.m. EDT.

Watch the first eight minutes of the first installment of the "Kate Plus 8" special here.