Kristen Smith also testified that when she left the boy in a plastic tote outside in freezing temperatures, she put him by the front corner of a gas station so she could make sure his electric blanket was plugged in.
Smith, of Aurora, Colorado, is charged with kidnapping 4-day-old Kayden Powell on Feb. 6 and abandoning him in West Branch, Iowa. A police chief found Kayden alive and well after the boy spent 29 hours in subfreezing temperatures.
Smith testified that her 18-year-old half sister, Brianna Marshall, had been having problems at home. Marshall's mother kicked her out of the house, Smith said, and with nowhere to go Marshall wanted to move to Denver to live with Smith and go to college.
The plan was for Smith to drive to Colorado by herself, and Marshall and the baby's father would join her a few days later, Smith testified.
They spent the night at the home of the baby's great-uncle in the Town of Beloit. Smith said she decided to leave at 2 a.m. to avoid driving through larger cities at hours when traffic would be worst.
Smith said she swaddled the baby and handed him to the father, 23-year-old Bruce Powell, but when she went to hug him goodbye he swayed unsteadily.
"He said, 'Here, take the baby,'" she testified. "I thought at first he meant, hold the baby while I get my feet together, and he said, 'Take the baby with you.' I said, 'Are you sure?' He said, 'Yeah,' and I was like, 'OK.'"
Federal prosecutor Julie Pfluger questioned why Smith would agree so quickly to such an unusual offer. She also wondered why Smith would take a newborn without checking with the mother.
A few hours after Smith started driving she got a frantic call from Marshall, who said something about the baby and then hung up, Smith testified. Smith said she tried calling Marshall back 14 or 15 times, but the call wouldn't connect. When she finally got through, the great-uncle answered and handed the phone to a police officer who ordered Smith to pull over, she said.
Smith, who was already facing legal trouble in Colorado because of an outstanding warrant in Texas, said she panicked. She decided to ditch the baby while police searched her vehicle, and then return to Wisconsin with Kayden, she said.
She pulled into a gas station, wrapped the baby in an electric blanket and placed him in a plastic tote. Then she placed the tote at the front corner of the station, plugged in the blanket and drove to another gas station about 500 yards away, she said.
FBI special agent James McMillan, who interviewed Smith on the day she took Kayden, said she repeatedly told him she didn't know where the baby was. She also never said anything about having the father's permission to take the boy, until after she knew the baby had been found, McMillan said.
Smith replied to most of Pfluger's questions by saying she didn't know the answer or didn't remember, even with simple questions such as where she was born, whether she lived in Wisconsin in 2010 and whether she'd ever been convicted in court.
At one point, frustrated prosecutors requested a private meeting with the judge and defense attorney. Smith waited on the stand, covering her eyes with the neckline of her sweater. When questioning resumed, she burst into tears and requested a break, then began wailing loudly as jurors left the courtroom. The trial resumed 30 minutes later.
Smith, who has four children and a stepchild, said she was pregnant about the same time as Marshall, but that she miscarried twins about a month before Kayden was born. She said she told no one about the miscarriages.
Testimony wrapped up Wednesday afternoon. Closing arguments are expected Thursday morning.