In the video the irate cyclist can be seen arguing with the man, telling him she was doing nothing wrong.
The incident unfolded in Victoria Park, East London, when the woman allegedly hit Freya "head on".
"The cyclist came flying out of the gate and her front wheel hit my daughter in the face," Grant told The Sun.
"It was awful. I was screaming and shouting 'you have just run over my daughter'.
"It fully took her out and her arm got caught in the spokes so she was dragged along the ground.
"I ran over and pushed the woman off the bike. She was on top of my child who was underneath the bike."
Grant shared the images on the Twitter in the hope the woman would be identified.
The woman reportedly claimed Freya ran in front of her.
Pedestrians are supposed to have priority in the park.
Police said inquiries were ongoing.
