HOUSTON, Texas (CNN) — The murder trial of a Texas woman charged with running her husband over repeatedly with her Mercedes will resume Friday following a day of drama in and out of the courtroom.

Against her attorneys' wishes, Clara Harris took the stand Wednesday, detailing her marriage to jurors. A short time later during a break, defense attorney George Parnham collapsed and was taken to the hospital.

Parnham was put on oxygen but was alert and talking before leaving for the hospital.

His co-counsel, Dee McWilliams, said Parnham has high blood pressure and had been feeling under the weather recently.

He was hospitalized, though colleagues said he was doing well Wednesday afternoon. District Judge Carol Davies said testimony would resume Friday morning.

Harris, 45, is accused of running over her husband David, an orthodontist, three times in her $70,000 Mercedes-Benz last July 24 in a hotel parking lot after catching him at the hotel with a receptionist he hired in April.

She claims the death was accidental and that she shouldn't be charged with murder. Prosecutors say it was intentional.

Harris faces life in prison if she is convicted of her husband's murder, but could receive a lighter sentence if the jury finds she acted in a sudden passion.

On Wednesday, a composed and often-smiling Harris spent about 90 minutes on the stand, describing a marriage that was a solid, loving relationship until David Harris began changing last spring.

Harris did not cover the night of the killing, but recounted clues she had of a shift in their 10-year marriage that began last spring. In probing her husband's mood shift, Harris said she asked her husband whether he loved her.

"He hesitated," she told the court. "He looked at me with a question mark on his face."

"What did that tell you?" asked defense attorney George Parnham.

"That he wasn't sure."

Harris described her husband going alone to the lake house for the first time, his irritability, and how she finally coaxed him to tell her what was bothering him. At that point, Harris said, her husband mentioned receptionist Gail Bridges.

"He said, 'I think you have to know there is somebody else,'" Harris said. "I asked him, 'Do you love her?' and he said, 'I don't know.' I asked, 'Do you love me?' and he said, 'I don't know.' I got emotional and started crying and shaking."

Harris said her husband apologized and tried to hold her, but she pushed him away. "I didn't want him to touch me," she said.

When Harris told him she would find a divorce lawyer, she testified her husband "grabbed me by the shoulders and said, 'I'd do anything for us not to get divorced.'"

There was only one thing Harris wanted, she told the court, and that was for her husband to fire Bridges. But at that point she still did not know the two were having an affair, just that her husband had taken Bridges to lunch and kissed her hand.

An employee told Clara Harris on July 16 that her husband had been seeing Bridges.

On Tuesday, Bridges testified that David Harris claimed to have an open marriage in which the spouses see other people. She testified Harris led her to believe the two had a future together.

Clara Harris had hired a private investigator to follow her husband to the hotel the night he was killed. The investigator caught portions of the attack on videotape, which has been admitted as evidence in the case.