A Long Island woman was busted on a felony DWI rap yesterday for driving while high on drugs with her 2-year-old grandson in her car, cops said.

Donna Catania, 54, of West Babylon, was pulled over by a Suffolk County cop at 10:30 a.m. not far from her home.

The officer “determined Catania was impaired by drugs,” and she was charged under Leandra’s Law’ with aggravated driving while intoxicated with a child in the car, endangering the welfare of a child and DWI.

Officers would not specify the drug involved.

Catania was being held overnight for an arraignment hearing today. The boy was released to a relative.

On her Facebook page, Catania described herself as: “Married, very happily . . . Grandma with a beautiful grandson! The light of my life.”

Leandra’s Law was passed after Leandra Rosado, 11, was killed in a 2009 drunken-driving accident when the minivan in which she was a passenger crashed on the West Side Highway in Manhattan.