If you’re having a hard time believing that Cara and Mady Gosselin are heading to college, you can only imagine how their mom Kate, 44, feels.
“It is the biggest mixed bag of emotions and stress I have ever faced,” Kate tells PEOPLE. “Mady and Cara really steered the ship in terms of applying to colleges; they knew what they wanted, and I trusted them. That same feeling is going to have to carry me through my fears now when I think about them going off on their own, fending for themselves, being alone for the first time.”
Cara and Mady, who were 6 when Jon & Kate Plus 8 began in 2007, are both “so excited” for the next step, but in their remaining time at home, they’re enjoying being “typical teenagers” and pushing their mom’s buttons, Kate says: “They think it’s hilarious to make me cry at a moment’s notice. They’ll say things like, ‘You know this is the last Christmas we’ll spend here while we’re living at home,’ just to catch me off guard.”
But the biggest waterworks came recently, when the band started to play “Pomp & Circumstance” at their high school graduation. “The first three notes played; I instantly started sobbing. That’s when it hit me,” she says. But she’s relying on “a little bit of denial” to get her through this summer in one piece, which “can be a good thing … it’s just too overwhelming to think in terms of ‘I’m not going to see them for so so long.’ You have to take it in increments.”
Also contributing to her mixed emotions: The fact that her girls will be going to different schools for the first time. “They agreed all along that they don’t want to go to the same school,” Kate says. “Their ambitions are so different that they really felt, there’s not one college that would fully answer what each of them wanted.” And while she’s proud of how both girls are approaching the change, from dorm shopping to roommate selection, there is one thing causing her stress.
“Within six days, Mady has to be dropped off, Cara has to be dropped off and the little kids begin their first day of high school,” she says, adding that she’s planning to make drop-offs short and sweet out of necessity. “The best advice I’ve heard is not to feel too obligated to stay and stay and stay: The kids don’t really want that; it’s eventually like, you have to be the one to drive away.”
With six 15-year-olds yet to graduate, Kate’s not quite an empty-nester just yet, but she says Cara and Mady’s absence will definitely be felt. “One thing I’m really going to miss is having them to guide their younger siblings. They’ve gotten so much closer with each passing year,” she says. “I worry about how much we are all going to miss them.”
It’s another family member who might convince the girls to visit home more often, though: their 10-year-old dog. “I don’t care if they only come home to see the dog—fine with me,” Kate says. “As long as they come home!”
For more on Kate’s best move-in tips and dorm room essentials, pick up this week’s issue of PEOPLE, on stands July 18.