By YVONNE VILLARREAL If Jennifer Love Hewitt ever needed a job to fall back on, taking calls as a 911 dispatcher would not be high on the list. “I’d be such a nervous nelly,” Hewitt insists. “I’d panic. I’d be the worst 911 operator. What they do is amazing. The pressure they are under and their ability to stay calm so that they can get someone the help they need is incredible.” Hewitt’s own inabilities aside, the actress can at least play the part. This season, she has joined Fox’s hit drama ”9-1-1,” as Maddie, the sister of firefighter Evan “Buck” Buckley (Oliver Stark). Her character becomes a 911 dispatcher in an attempt to restart her life after leaving an abusive relationship. The role marks Hewitt’s return to TV after nearly three years away — an intentional break motivated by the birth of her second child, Atticus, now 3 (her daughter, Autumn, will be 5 in November) and the enduring grief over the death of her mother in 2012. “...