HOUSTON – A school bus driver accused of being intoxicated while driving with children aboard her bus blamed the ordeal on an upset stomach.

Linda Sue Godejohn, 55, of Cleveland, was charged with driving while intoxicated after authorities said she “miserably” failed a field sobriety test when she was pulled over Thursday afternoon near Hirschfield and Aldine Westfield roads in Spring.

Godejohn posted a $100 bond and was released from the Harris County Jail on Friday morning.

The Harris County District Attorney's Office announced Friday that it plans to upgrade the charge against her to driving while intoxicated with a child passenger, which is a more serious felony charge.

"We discovered that one of the children on the bus was under the age of 14 which triggers a higher charge a felony charge for DWI," said Sean Teare, with the district attorney's office.

Witnesses said they called 911 after they noticed the bus swerving. One witness said the bus veered onto the left shoulder of a road, hit a divider wall and then back onto the road. Investigators said they pulled the bus over after they noticed erratic driving, including a sharp turn that nearly caused the bus to roll over.

Linda Sue Godejohn is seen in this mug shot released by the Harris County Precinct 4 Constable's Office on May 31, 2019.

“I don’t drink,” Godejohn said as she left the jail. “I have not drank in years.”

Godejohn said a doughnut she ate at the school upset her stomach and that’s what caused the unusual driving.

“My stomach was just hurting so bad that a wheel fell off the thing, the curb,” Godejohn said. “That's all it was, and going 45 mph, it’s going to whip back.”

As to why authorities said she flunked the sobriety test, Godejohn said it’s not an easy test to pass.

“Because it’s hard,” Godejohn said. “I mean, I couldn’t even do it right now.”

VIDEO: Bus driver speaks after being released from jail

Authorities said as many as 30 students from YES Prep Public Schools’ North Forest campus were aboard the bus at the time Godejohn was stopped. Godejohn said parents should know that their children are safe.

“They have been riding all year long,” Godejohn said. “Nothing has changed.”

Investigators said a blood sample is being analyzed to determine if Godejohn was intoxicated.

The company that Godejohn works for,Today the First Student, released the following statement:

"The driver was immediately removed from service pending the outcome of the investigation. Safety of the students we transport is paramount. First Student is partnering with the local authorities. Since this is an active investigation, we are unable to comment further."