Write down the child's address. Be sure to have all of the information, including street numbers, street name, city, state and zip code. Not only do you want the child to be able to remember her full address, but it will be easier to write a song with more information to fill in the blanks.
Ask the child for more information about her house and neighborhood. Find out what color the child's house is, if there are any stores nearby, if she has any friends next door, etc. Get enough information as you can about the house and the child's life so as to create a song that ties the address with a mental image of the child's home.
Come up with a melody based off of the lyrics or fit your lyrics to a pre-existing melody. It can even be the melody to an already popular children's song, such as "Twinkle, Twinkle Little Star" or "Mary Had a Little Lamb."
Write the child's address as the chorus lyrics of the song. This is important as the chorus will repeat several times throughout the song, reinforcing the child's address. Keep the melody simple and easy to sing along to.
Write the verse with the other information about the child's life in mind. Perhaps the first verse in the song can be about the fun things the child likes to do at the house. It can be about anything as long as it's recognizable and important to the child and leads up to the vital information in the chorus.
Play the song for the child slowly. Sing it slowly with one phrase at a time to allow the child to soak in the information. Sing one line in the song and have the child repeat it until they memorize the part.
Once the child knows the lines in the song, utilize clapping and/or hand motions to drive home the rhythm and images in the song. For example, if the song mentions the house's driveway, make hand motions that mimic driving a car and have the child do this as well.
Play the song full through until the child knows all of the words and can repeat her address without your help.