Jenna Saucedo-Herrera’s path from a working ranch in Elmendorf to the executive ranks of one of San Antonio’s largest employers wasn’t one she carefully mapped out. Instead, she says, it was built by embracing challenges, taking on difficult assignments and investing in relationships.Saucedo-Herrera, head of corporate impact at USAA, shared her story during an appearance on KSAT’s “Pickup Lines” with host Ernie Zuniga.Raised on a ranch just outs…