"I tried to get on. Suddenly, the driver said: 'You cannot,'" she told CBC News. "I said: 'Why?' He said: 'We don't have room for you.'"
Guo said the bus was not full at the time. She also said that the driver let other people on.
She said that she told the driver that her baby was cold, but she was told he could not help her.
Guo said her baby got sick after being left in the cold.
She said people riding public transit need to shift their attitudes about transit and stop making her feel unwanted.
MiWay is investigating the incident.
Click on the video above to see a full report from the CBC's Kate Adach.