Petara Cordero was killed after being hit by a car while the two were hit by a broken tire. Brown shared pictures and videos from Cordero on his Instagram Friday.
"She's in a better place now and she can just rest," Brown said. "My wife, my best friend, and my beautiful daughter's mother, I love you, baby."
Just last month, Brown released another picture of Cordero announcing the birth of her daughter, Haven Harris Smith.
Shortly thereafter, a woman in a 201
Police and paramedics arrived shortly afterwards.
Cordero was taken to hospital, where she was pronounced dead. The driver of the second car was also taken to the hospital and released after treatment.
A toxicological report is pending, but the woman admitted that she had been drinking, the police said. Smith was not affected, police said.
The incident is under investigation and no charges have been filed at this time.
The Browns said the players were notified during a team meeting. Head coach Freddie Kitchens also visited Smith at his home.
"Words can not describe the suffering we feel for Chris after losing his girlfriend Petara," team owners Dee and Jimmy Haslam said in a statement. "Our entire organization mourns the loss of Chris, his family and the Cordero family, and we will do our utmost to provide our support, comfort and resources during this most difficult time."
The Browns will have on-site counselors throughout the week to provide emotional support to players and staff.
Mary Cay Cabot of Cleveland.com says the daughter of Cordero and Smith was born four weeks ago. Smith was excused from the preseason game of the Browns against the Indianapolis Colts in August so he could attend the birth of his daughter.
The 27-year-old Smith was drafted by the Jaguars in 2014. He has been with the Browns since last year.