The wreck happened just before 10 p.m. in the 1700 block of S. Main near Pin Oak. This is just north of I-10 East Freeway.
The woman and the baby, who authorities say was properly restrained in a child seat, were in a white Chevy Silverado truck headed northbound on S. Main.
A man driving a black Chevy Silverado truck was traveling southbound on S. Main when he veered into the oncoming lanes, hitting the woman's truck head on, deputies said.
Both drivers were killed.
The baby girl's legs and one of her arms are broken. She was flown to Memorial Hermann Hospital in the Texas Medical Center, where she's in critical condition.
"The fact that the little one was properly restrained in a car seat likely saved her life," Harris County Sheriff Ed Gonzalez said.
Gonzalez said the woman was wearing a seat belt, but the man was not.
"The male got behind the wheel and put not only himself in danger, but other people. He ruined not only that person's life, but others that surrounded her," Gonzalez wrote in a tweet.
Officials say they detected a strong smell of alcohol coming from the black truck.
Authorities plan to take inventory of the black truck to see if they can find evidence of alcohol consumption or receipts.
Last night, a fatal collision occurred at 1700 S. Main in the Highlands area. An adult male, suspected of driving intoxicated, struck an adult female driver (32) head-on. Also in her truck, was her 2-yr-old. The toddler sustained broken bones, but is stable. https://t.co/RYS1Fxnaej— Ed Gonzalez (@SheriffEd_HCSO) January 8, 2021
Follow Courtney Fischer on Facebook, Twitter and Instagram.