Kate and ex Jon Gosselin's rarely-seen daughter Mady turned up in her younger sister's TikTok content this week - and now, mom is reacting! So, 21-year-old Hannah Gosselin popped up on TikTok with a few new posts on Monday. In the most notable one, she shared a wonderful and heartwarming video alongside her 25-year-old sis Mady, who doesn't tend to live life in the public eye that much! Related: Kate Goes IG Official With Former Bodyguard Boyfriend Steve Neild! The duo were in New York City, and they used their outing to dance on camera together to the 2013 Lorde track A World Alone.