They grow up so fast.

A Pennsylvania 12-year-old girl and her 14-year-old sister jacked the same car twice in four days — only to crash it while zooming away from cops, according to reports.

The pint-sized speed demons allegedly swiped a Hyundai Tucson SUV that the owner left running in front of her Hummelstown home Wednesday, police sources told PennLive.com.

When the owner returned, the ride was gone — but it was found with no keys inside the same day, police told the outlet.

Cops urged the car owner have the vehicle re-keyed and to buy a club to lock her steering wheel to prevent another theft.

But on Saturday, she heard someone start her car and drive away — again.

A Hummelstown Police officer later saw the vehicle and tried to pull it over, prompting the mini-Thelma and Louise duo to flee.

The sisters, who have not been named, then slammed into several parked vehicles as cops chased them, according to police.

The small-time crooks were arrested but not injured.

They were charged with theft, fleeing police, reckless endangerment, careless driving, driving without a license and causing a hit and run accident, police said.