Handcuffed and wearing a pink and white striped prison uniform, McClain told the judge that she understood the charges against her. The judge delayed McClain's bond hearing to give her court-appointed attorneys more time to work on the case.
The capital murder charge carries a potential death sentence.
Authorities said McClain was so desperate to find a child that she went exactly where she knew she could find one: the pediatric clinic where she had taken her three children for checkups.
But when McClain went to the clinic this week, her choice of which child and mother to target appeared to have been random.
"There is nothing to indicate this was anything beyond planning further than" going to the clinic, Capt. Bruce Zenor of the Montgomery County sheriff's office said.
McClain saw her chance when Golden and her newborn son, Keegan Schuchardt, were leaving his first checkup Tuesday afternoon at Northwoods Pediatric Center in Spring, about 20 miles north of Houston.
Authorities said McClain had parked next to Golden, and as Golden was placing Keegan into her pickup truck, McClain shot her, snatched the child from the truck and sped off. The dying woman leaned into the vehicle and tried to take the boy back, screaming: "My baby!"
Golden died at a hospital. Her son has been reunited with family members.
Montgomery County Sheriff's Detective John Schmitt said McClain, who authorities say admitted shooting Golden and stealing the baby, does "appear remorseful for what happened."
McClain's estranged husband said he was shocked at the events of recent days.
"I can't believe she shot someone. That's not Vera," Theo McClain, of San Diego, told The Associated Press. A relative in Houston has been looking after the couple's three children since McClain's arrest.
McClain is a vocational nurse at a local staffing agency, a job that involves providing basic nursing services under the direction of registered nurses and doctors. She holds vocational nursing licenses in California and Texas and has not faced disciplinary action in either state, according to licensing boards.