After years spent in its “first-ever huge campaign,” says Principal Sister Charlotte Lange, the region’s only all-female Catholic high school is growing its physical space at last. And she’s a little nervous.

Lange’s approach is unconventional if not risky. So far she’s raised $4 million of the $7 million needed to complete the expansion that calls for a new 40,000-square-foot athletic facility, a new library, science labs and conversion of the convent into more science labs. And with the convent gutted, the three remaining Benedictine sisters have made a new home in a nearby house.

Some close to Lange had told her hold off on construction until the money was in hand. But Lange is pressing on. Her immediate goal is to raise $400,000 by December. “We’re building a shell,” she says, but it’s a shell built on faith that her former students will come through. “We need to educate women in terms of philanthropy,” she says. “They don’t realize it’s payback time.”

Admittedly, Lange says fund-raiser is not her favorite role but likens her task to parents who will do anything for their kids. “I’m passionate,” says the 62-year-old nun, renowned for her tireless exuberance.

Lange says now that school is back in session, the construction presents some parking challenges for students and faculty. And although she personally presented flyers to neighbors about the enormous undertaking, not all of them are pleased. She discovered one of them on school property with a Geiger counter in hand, questioning the work. Lange quelled his concern.

Saint Gertrude has an enrollment of 262 — slightly down from 2002 — and tuition is $8,500 a year — slightly up from 2002. The last addition to the campus was in 1973 and that building cost $300,000, Lange says. But Lange, who graduated from the school in 1958, seems undeterred by what she must raise now. “This is a one-shot deal,” she says, adding: “It was either move ahead and do what we have to do or shut down.” — Brandon Walters