She started with Legos, the Danish snap-together blocks kids use to build little worlds. And Arduino, the Italian open-source controller system popular with autonomous-device makers, referred to by some as the Lego brain.

“I was doing this in sixth grade,” says fast-moving Lindsey Turner, now 15 and a sophomore at Westtown School, where she is head programmer for the robotics team.

The Chester County school this weekend is hosting FIRST’s — For Inspiration and Recognition of Science and Technology — regional heavyweight-robots competition, where 1,200 high school students from Pennsylvania, New Jersey, and Delaware square off with creations weighing up to 125 pounds. (That’s bigger than Turner.)

With business sponsors such as Boeing and TE Connectivity, the event is as much about inspiring youths to pursue careers in STEM — science, technology, engineering, and mathematics — as it is about creative fun. It comes days after the National Center for Science and Engineering Statistics released a report that women, people with disabilities, and minorities from three racial and ethnic groups (black or African American, Hispanic or Latino, and American Indian or Alaska Native) are underrepresented in science and engineering, and following an announcement Tuesday that Philadelphia-area TechGirlz has been acquired by the Illinois-based nonprofit Creating IT Futures in a deal designed to build a more robust pipeline of women interested in technology careers.

“We get the kids drunk on Legos in middle school. Once they get them moving autonomously, they are hooked,” said Paul Kloberg, a retired New Jersey physics teacher and treasurer of the regional FIRST affiliate. The national organization, based in Manchester, N.J., was founded by Dean Kamen, the medical-device developer famous for his battery-propelled Segway personal vehicles.

On Saturday, Turner and her team were running last-minute checks on their machine before wheeling to the center of the Westtown gym floor to join two allied teams and three opponents in the first of 12 two-and-a-half-minute courses.

Five-member operating teams prepared their machines to pick and lift kickball-size payloads, pack them into rocket models, slide hatches in place to boost rocket capacity, and then power them up steep, slippery inclines, pivoting for points that would guarantee the best a choice of runoff competition partners, trips to regional championships at Lehigh University, and even the national contest in Detroit.

Turner wasn’t born into a family of engineers. But she found a home in Westtown School’s robotics program, which enrolled six boys 10 years ago and now totals 40 -- including 16 girls and more than one-tenth of all the students in the high school, said Steve Compton, robotics coach and sciences department chief.

In the gym stands, members of Kennett High School’s Demon Robotics team, wearing sky-blue T-shirts, were on their feet cheering two drivers, a drive coach, a player, and a technician as they urged their robot through its first-round competition. They chanted the team’s FIRST number -- “Four-three-four-two!" -- as its three-team alliance edged opponents, 38-30.

Their edge? “Our robot has an arm that goes 360 degrees without an elevator, so it’s not dependent on which way we are facing," explained Molly Hohner, 18, president of the Demons, as little plastic horns wired over her head glowed intermittently. “And our system for intaking the balls can go in any direction. It helps speed the process. Our climb isn’t unique, but it can tilt quickly.”

One of 10 females on the 50-member team, Hohner is founder of Kennett High’s Society of Women Engineers club, and plans to start engineering school in September, either at Penn State or Purdue.

Members of the team from all-girls Mount Saint Joseph Academy in Flourtown were jubilant their side racked up 53 points in its match, the most of any group at that point in the day. Pit crew members Kristen Neill, 16, and Ellie Slawek, 17, explained they chose to install fat-threaded lead screws instead of more common -- but potentially cumbersome -- hydraulics in their successful bid to power the robot up platforms faster.

“We hope we can seed that desire for creativity, innovation, and problem-solving," said Kevin Kelley, a senior product manager at event sponsor TE Connectivity, which has management offices in Berwyn. “That’s what we are going to need when they come into the workplace."