Actually, EXID's Hani had already revealed this earlier this year, but now you can hear Ji Eun's side of the story! On the July 3 episode of KBS' 'Yoo Hee Yeol's Sketchbook', she talked about how she used to be a JYP Entertainment trainee.
Ji Eun said, "At the time, BESTie's member U.JI, EXID's Hani, and SISTAR's Hyorin were with me. The four of us were preparing to be the 'Little Big Mama'. But because of various reasons we were dispersed and separated."
He also asked, "Have you seen J.Y.Park since?"
She said, "I met him once at a broadcast station, and he told me, 'You're doing well,' and left." He replied, "Even though he said that, he was probably crying tears of blood (bitter tears)," making people laugh.
All four of them match perfectly with their respective groups now, but it's interesting to think of 'what if'!