Kate Penland said she and her son, Garren, boarded the Continental Express plane last month in Houston on a trip from Atlanta to Oklahoma via Houston.
"As we started taxiing, he started saying, 'Bye, bye plane,'" Ms. Penland, who lives in suburban Atlanta, told WSB-TV in Atlanta.
The stewardess objected, Ms. Penland said.
"At the end of her speech, she leaned over the gentleman beside me and said, 'It's not funny anymore. You need to shut your baby up,'" Ms. Penland said
Ms. Penland said the stewardess also said, "You know, it's called baby Benadryl."
"And I said, 'Well, I'm not going to drug my child so you have a pleasant flight,'" Ms. Penland told the TV station.
She said the flight attendant announced they were turning around and that Ms. Penland and Garren were going to be taken off the plane.
"I was crying, I was upset and I was thinking, 'What am I going to do? I don't have anything with me. I don't have anymore diapers for the baby, no juice, no milk,'" Ms. Penland said.
Ms. Penland did not continue on the flight, said Kristy Nicholas, spokeswoman for ExpressJet Airlines. She said ExpressJet flies as Continental Express for Continental Airlines.
Ms. Nicholas said, "We received Ms. Penland's letter expressing her concerns and intend to investigate its contents."
Ms. Penland said she later learned the flight attendant told the pilot that she was threatened. Ms. Penland said that never happened.
A fellow passenger told WSB that none of the other passengers had problems with Garren and that Ms. Penland never threatened the flight attendant.