Naya Rivera's Dad on How Motherhood Transformed Her and Her Final Act of Strength (Exclusive)

Authorities said they believed the late actress pushed her son back on the boat to safety but couldn't save herself.

Naya Rivera lived for her son, Josey

Thursday, July 8, 2021 marks the one-year anniversary of the Glee actress' death, which occurred after she went missing following a boat ride with her then-4-year-old son, Josey, on California's Lake Piru. Her body was recovered five days later.

ET's Kevin Frazier sat down with the late actress' father, George, for an emotional conversation ahead of the anniversary, and he talked about how Naya changed after becoming a mother.

Naya gave birth to Josey, whom she shared with her ex-husband, Ryan Dorsey, in September 2015. George told ET that Josey was definitely Naya's number one priority.

"He really became everything for her," he said. "Her focus was really on him and he was growing up as she was becoming a mother, she really leaned into that, really leaned into that and the word I want to use is maturity. She became very mature as a person and really receptive to other people's feelings."

"I watched the maturity in her after she had a child, before and after, big difference," he added.

Naya was pronounced dead on July 13. Authorities later shared that they believed that just before Naya's death, she mustered enough energy to push Josey safely back onto the boat as the boat started drifting, though couldn't save herself. When asked what that final heroic act says about Naya, George shared, "Sort of the same mantra she used for life, you know, preservation, keep going, when things are hard, you keep pushing. It just shows you the strength of the person."

George said that the now 5-year-old Josey does frequently ask about his mother and they don't shy away from the conversation.

"He says, 'Oh, I used to do this with Mommy. Oh, I remember Mommy used to do this,'" he shared. "It might be a cup out of the cupboard, it might be a snack and we go, 'Yeah, remember when you did that?' We don't back off of that, we just keep reinforcing his values and our values."

"Tough situation, especially because he was there -- it's not like you're talking about a ghost that's floating around, right?" he added. "He's got memories as well, but boy is he coming around, right? Really strong kid. We handle him and we talk to him just like he's a 5-year-old going on six. It's no different but when he wants to talk about his mother, we talk about his mother, in conversation. He's growing up and handling it really well."

These days, the family is focused on Josey's well-being. George's younger daughter, 27-year-old Nickayla, has stepped up to help 37-year-old Ryan care for Josey. He said Nickayla and Ryan are "doing a really great job" and noted that Naya's family -- including her 30-year-old brother, former NFL player Mychal Rivera -- will always be there for Josey.

"I know I won't see [Naya] again but me, Mychal and Mikayla -- we have Josey," he said. "We've taken care of him, he'll be fine."

ET also recently spoke to Taj Mowry, who dated Rivera in 2000 for four years, and he said he hopes others will remember Naya for the incredible mother she became.

"I think overall the amazing mother that she became and the working mother that she became. I think she's the spitting image of what women are capable of doing just as capable as men are," Mowry shared. "She was so strong, she was hilarious, oh my God, and so talented, so talented. Her voice always was the best I had ever heard."

Meanwhile, a source told ET in April that Josey is doing really well.

"He’s the sweetest, happiest little boy and there is no shortage of love in his life," the source said.