Mary Su was sworn in Wednesday as Walnut’s first female Chinese-American mayor, Bethania Palma Markus reports today.

The change in leadership between former Mayor Joaquin Lim and Sun couldn’t have come at a more contentious time — Walnut is putting up its gloves in a heated battle against Ed Roski Jr.’s proposed NFL stadium in Industry.

The project cleared a major hurdle Thursday, getting approval from the Industry Planning Commission.

In recent weeks, we’ve heard a lot of speculation from angry residents who argued Lim wasn’t doing enough to fight the planned 75,000-square-foot stadium.

But it seems Su’s commitment is being questsioned as well: recall papers have been filed against her and Councilwoman Nancy Tragarz for the same reason.