Kate Gosselin's twin daughters turned 17 in October and have "limited time left at home," the mother of six revealed on Instagram Wednesday

Kate Gosselin is “cherishing every moment” that she has with her twin daughters before they leave for college.

The Kate Plus 8 star took to Instagram Wednesday, when she revealed that 17-year-old twins Mady and Cara Gosselin have “limited time left at home.”

Kate, 42, shared a photo of Mady taking a mirror selfie, in which she donned a grey turtleneck, ripped jeans and had her hair pulled back in a low, messy bun.

“❤️ #GrowingUp #Beautiful #Mady #LimitedTimeLeftAtHome #CherishingEveryMoment,” she wrote in the loving caption.

In honor of the twins’ 17th birthday in October, Kate — who also shares 13-year-old sextuplets Aaden, Alexis, Hannah, Leah, Collin and Joel with ex-husband Jon — posted a throwback photo of the girls to social media.

“Happy birthday to my girls! My heart hurts because you’re almost adults and will soon leave for college, yet it smiles because I am seeing who you’ve become: brilliant, beautiful, kind, caring, logical, responsible, empathetic, honest, amazing individuals!” Kate wrote in the tribute post.

“I love you both SO VERY MUCH! Let’s have a wonderful day together celebrating Y❤️U!” she continued and added the hashtags “#Cara #Mady #SeventeenthBirthday #ILoveYou #ForeverAndAlwaysNoMatterWhat.”

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Credit: Larsen & Talbert

For the past 16 years, the Kate Plus 8 star’s home has been anything but quiet. But within the next half decade, all of her children will be graduating high school and contemplating next steps, including college.

“It’s the day I have feared since they were born,” she said in a previous Kate Plus 8 promo about her sextuplets becoming teenagers. “To think that when the little kids are in college and my house is empty? I can’t fathom it.”

WATCH: Story Behind the Story: Behind the Scenes at The Gosselin Family Photo Shoot

Speaking with PEOPLE in fall 2016, Kate opened up about what she predicts the next decade of life will be like for her.

“I’ll be the crazy cat lady … except with dogs,” she said.

“I’ve learned not to have any predictions about the next 10 years, because I certainly never thought I’d have wound up here 10 years ago!” she shared. “Given all the drama of our lives, doing a reality show honestly feels like the smallest issue we’ve ever had to deal with.”