"Once you go through that two times, you’re like, ‘Oh I have some strength I didn’t know I had,' " the 'Beyond the Gates' star tells PEOPLE Karla ... upstairs in a pool," she says, "So ...

"Dani doesn’t shrink, and she doesn’t hide," Mosley tells PEOPLE in an exclusive interview ... I had both of my kids upstairs in a pool," she says, "So it’s like once you go through ...