AS Caitlyn Jenner plays tennis with her sister, the 65-year-old mocks her own athletic prowess with the quip “Bruce was a better tennis player than Caitlyn.”

    It’s a moment of comic relief in an otherwise emotional first episode of “I Am Cait,” an eight-part docuseries premiering Sunday on E! that pulls back the curtain on the new life of Jenner, the most high-profile transgender American, an Olympic champion formerly known as Bruce.

    Before Jenner came out in an interview with Diane Sawyer in April and appeared as Caitlyn on a Vanity Fair cover, the 1976 Olympic decathlon winner had been a staple of E! for 10 years as the patriarch on top-rated reality show “Keeping Up With the Kardashians.”

    It’s clear from the beginning of “I Am Cait” that she is on a mission to educate about the challenges for the transgender community, particularly for young transgender people, and for families of people who transition.

    There are many hair and makeup sessions, and time in the closet where Jenner and famous stepdaughter Kim Kardashian peruse dresses sent over by designers Tom Ford and Diane Von Furstenberg.

    But before the fussing, and in the opening scene, Jenner is stripped of makeup and sleepless at 4:30 a.m. as she worries about helping transgender youth who are thinking of killing themselves. She’s had those thoughts too.

    Jenner doggedly dodges paparazzi to make a visit to the family of a 14-year-old transgender boy who killed himself. She and the mother talk about how to help transgender children and the show wraps with a suicide hotline number.

    Early reviews for the show, which will air in over 150 countries, are positive. “At times the tone can be stiff and cautious, like a public-service announcement,” wrote Time.com critic James Poniewozik.

    Esther Jenner pays her daughter the ultimate compliment, saying she didn’t think she could be prouder than when Bruce stood on the Olympic podium but is more so now for the courage Caitlyn has shown.(SD-Agencies)