Yanira Maldonado of Arizona, who denied the charges, was freed Thursday after a judge determined prosecutors didn't provide evidence, CNN reported.
She and her husband, Gary Maldonado, returned to Arizona early Friday.
Security camera footage played in court Thursday shows Maldonado and her husband boarding a bus in Mexico last week, carrying a purse, two blankets and two bottles of water. Defense attorney Francisco Benitez argued that the video showed nothing they carried could hold the amount of marijuana Yanira Maldonado was accused of smuggling, indicating someone else brought the marijuana onto the bus.
"That was the key that would help us prove her innocence," her husband said. "It showed right on the film clear as day there's no way you could carry 12 pounds or 5.7 kilos with one arm."
In an interview with CNN Wednesday, Maldonado, a Mormon, said she relied on her faith and family to survive.
"Reading the Scriptures, reading the Book of Mormon, praying, fasting," she said. "And all the support that I've been getting from my family, my husband, my children and everybody out there reaching out to help."
The Mexican military officials who arrested Maldonado haven't presented their case yet, CNN said. The soldiers didn't show at a scheduled appearance Wednesday.
Yanira Maldonado was arrested May 22.
The Mexican Defense Ministry said troops conducting a routine investigation stopped the bus Maldonado was riding and found a substance that appeared to be marijuana under her seat. Troops turned the case over to the Mexican attorney general's office, the ministry said.
Maldonado was held in a women's prison in Nogales.