The woman told her daughter, who called Avello to warn her not to go outside.
"I looked out of the side window on my front door and there he was, sitting there," Avello told Coral Springs Talk.
Avello said she called the Broward Sheriff's Office, which referred her to the Florida Fish and Wildlife Conservation Commission.
She said officers arrived within 30 minutes, bound the 5-to-6-foot alligator's mouth, and hauled it away for parts unknown.
"I'm sure he was just looking for a body of water, but stopped here along the way," Avello said.
Experts said alligators are frequently found wandering through residential areas this time of year, which is the reptiles' mating season.