Kris was there when Chyna was in labor
, and even participated in the mannequin challenge
that took place in the delivery room. "It was Chyna and her girlfriends who said, 'Let's do this,' and I thought that was such a great distraction," the 61-year-old momager
recalls. "I was always so nervous in the delivery room, so I gave her a lot of credit because she was so excited and nervous but still wanted to do something to make everybody laugh!"