My sister flew to Florida from Toronto with a letter written by her husband saying she could take the baby.
All phone numbers were on the letter.
It was not notarized-She was so sure they would not let her on the plane. They gave her a very hard time.
It was touch and go but they did let her fly-She said she would never fly without a notarized letter again.
I take my older nieces to florida each year with a letter that is not notarized but because they are old enough to say that they know me and want to go there is never a problem.
It is because the baby is too little to speak for herselve.