Houston (CNN) The mother of a missing Houston girl has denied allegations that the child had been abused at home, and says the head injury that led to those allegations was discovered only after a series of hospital visits. 

Maleah Davis, 4, and her two brothers were removed from their home and placed with a relative last year after allegations of abuse, the Texas Department of Family and Protective Services told CNN. 

A judge ordered their return home in February and called for child protective services to visit the home at least once a month to check on the family. 

Maleah has been missing since late last week.  According to her stepfather, Darion Vence, he, his 1-year-old son and Maleah were abducted on the side of a road Friday night in the Houston area by Hispanic males who knocked him unconscious. 

When he finally awoke Saturday evening, Vence told detectives, he was on the side of a road with his son and Maleah was gone.  In an interview Tuesday with CNN, Maleah's mother, Brittany Bowens said Vence's story doesn't "make sense." 

Bowens also addressed Maleah's head injury.  Houston police Sgt.  Mark Holbrook has said Maleah had had multiple brain surgeries, including one in recent months. 

The surgeries were intended to help an injury heal, he said. 

Bowens on Tuesday disputed allegations that her daughter was physically abused at their home, and gave this account of the injury:

Bowens said she took her daughter to West Houston Medical Center last July because she was lethargic, but nurses didn't examine her head. 

Weeks later, on July 28, Maleah fell while she was sitting at the table eating by herself, Bowens said. 

"When she falls, she came around that couch, she had a deep gash in her head and it freaked me out," said Bowens, who again rushed her daughter to West Houston.  Doctors discharged Maleah without performing a CT scan, Bowens said. 

Five days later, in early August, Maleah suffered a seizure, Bowens said, sobbing.  Maleah was taken to a children's hospital. 

"They did a CT scan and that's when they told me there was bleeding on the left-hand side of her brain," she said. " At that point it was a life or death situation." 

Doctors operated on Maleah, she said.  A few days later, officials with Child Protective Services arrived at her home, Bowens said. 

"They didn't find anything because we're not those kinds of people," she said. 

But that month, child protective services placed Maleah and her two brothers with relatives -- an arrangement that continued until the judge ordered them returned home in February. 

Now, police are on the hunt for the trio of suspects Vence described, their reported blue pickup truck and the young child. 

Maleah is about 3 feet tall and weighs 30 to 40 pounds.  She was last seen wearing a light blue Under Armour jacket, blue jeans, gray Under Armour tennis shoes with pink and white details and had a pink bow in her hair. 

Here's everything we know about the young girl and how she went missing:

Stepfather says he kept passing out

Vence told detectives that he, Maleah and his son were on their way to the airport Friday night to pick up Maleah's mother, who was flying in from Massachusetts, Sgt.  Holbrook said. 

While on the road, the stepdad says he heard a "popping noise," like a popped tire, and pulled over to check on it, he told police.  That's when a blue pickup truck pulled up behind the car and two Hispanic males got out, according to Vence's narrative to police. 

One of the men commented, "Maleah looks very nice, looks very sweet," according to Vence's account. 

The other man hit Vence in the head and he lost consciousness, he told police. 

Stepfather Darion Vence says one of the abductors hit him in the head

At some point when he woke up, Vence said he was in the back of the truck with Maleah and her brother and three Hispanic males were also in the vehicle. 

He told police he was in and out of consciousness until about 6 p.m. Saturday, when he woke up on Highway 6 with the 1-year-old boy.  Maleah was not there. 

Vence said he walked to a nearby hospital where he received treatment and reported her missing. 

The stepfather's story has "a lot of blanks," Holbrook said, but he said he's hoping the public can help them "fill in the blanks" in the narrative provided to them by Vence. 

Mother asks for help

Maleah's mother told CNN affiliate KTRK she feels "so lost." 

Through sobs, Bowens pleaded for help, saying losing the young girl is "too much to bear." 

"I can't concentrate, I can't focus," she told the affiliate . " It's so overwhelming for me.  It doesn't seem real." 

The mother was returning from a trip and got another family member to pick her up from the airport when Vence didn't show up with the children, Holbrook said. 

"(There's) so many thoughts going on in my mind on what could have happened," she told KTRK. 

Maleah, she said, is a kind, loving, creative and smart young girl. 

Volunteers join search

Texas EquuSearch, a search and rescue organization, has joined the effort to look for Maleah.  The organization said on its website an active search began Monday morning. 

EquuSearch founder and director Tim Miller told KTRK he's "hoping for the best, expecting the worst." 

"No matter what the case is, I hope this baby is found," he told the affiliate. 

These are the cars police are looking for

Police posted a representative photo of the blue pickup truck that Vence said the abductors were driving. 

Police say a blue truck similar to this one may have been used in the abduction of Maleah Davis. 

An Amber Alert describes the car as a blue, crew-cab Chevy pickup truck, possibly a 2010 year model. 

The car Vence was driving -- a silver Nissan Altima belonging to Maleah's mother -- is also missing, police said. 

A traffic camera captured an image of the Altima driving through an intersection in the Houston suburb of Sugar Land just before 3 p.m. on Saturday afternoon. 

This image captures the Nissan Altima on Saturday, during the time Vence said he was in and out of consciousness. 

Houston police ask anyone with information about the case to call 713-308-3600. 

Correction: A previous version of this story incorrectly spelled the name of Brittany Bowens.