She immediately broke into tears when she was asked by Deputy District Attorney Jeff Dusek to name her children and give their ages.
She regained her composure and began to testify about visiting defendant David Westerfield's home with Danielle and one of her brothers to sell Girl Scout cookies, and about Westerfield buying her and her friends a drink at a bar early on the morning of her daughter's disappearance.
She said she smoke marijuana before leaving home.
Van Dam came to the stand after a medical examiner, Dr. Brian Blackbourne, testified that he could only estimate the time of death as 10 days to six weeks prior to the autopsy.
Blackbourne also said he concluded the girl's death was a homicide from the position of the body, its location far from her home and because searchers had been looking for her for three weeks. Under questioning by the defense, Blackbourne said there was no evidence the girl was strangled and there was no evidence of sexual assault.
Dr. Norman "Skip" Sperber, a forensic dentist, testified that four of Danielle's teeth were missing when he examined her mouth, but that he later found one.
Sperber, under questioning by Dusek, testified that teeth commonly fall out during decomposition, but that none was found under the body after it was discovered Feb. 27 near a tree in Dehesa.
In opening statements, the prosecution suggested that the loss of teeth showed Danielle could have been suffocated, that her teeth could have been knocked out by a forceful hand against her mouth.
Most of the testimony Wednesday came from the girl's father, Damon van Dam, who admitted he lied to police about smoking marijuana the night before his daughter disappeared when police first started investigating the case.
Once he realized the gravity of situation, he said that he was completely frank about the events leading up to the girl's disappearance sometime late Feb. 1 or early the next morning.
Van Dam also testified that he had engaged in past extramarital intercourse with the same two women who went out with his wife the night before he reported his daughter missing.
Westerfield, 50, a self-employed design engineer who lived two doors away from the van Dams in Sabre Springs, is charged with murder, kidnapping, possession of child pornography and the special circumstance of murder during a kidnapping. He could get the death penalty if convicted.
Soon after the search for the second-grader began, rumors about the van Dams' so-called swinging lifestyle fueled speculation that their behavior could have had something to do with her disappearance.
Van Dam, 36, said Barbara Easton and Denise Kemel went with his wife on a "girl's night out" to Dad's Cafe in nearby Poway the night of Feb. 1, because Easton was scheduled to be transferred out of town.
Defense attorney Steven Feldman dwelled on the subject of his relationship with the other women, questioning the Qualcomm software engineer about when and where he had sex with them.
Feldman also quizzed him about kissing and massaging Easton in his bedroom after the women returned after a night on the town.
Van Dam testified that he did not notice his home security system indicated that any doors or windows had been opened after he put Danielle to bed and before the women returned.
Van Dam fell asleep, woke about two hours earlier and, at that time, testified that he did such an indicator. He testified that he also checked a garage door.
Much of the early testimony was designed to orient jurors -- six women and six men -- to the layout of the van Dam home. Van Dam described the upstairs hallway that led to bedrooms and Danielle's room.
Van Dam said he and wife Brenda "got very nervous very quickly" when they discovered Danielle missing the morning of Feb. 2. He searched outside and noticed their side gate, which is difficult to open, ajar.