Three good poems for a granddaughter's birthday are "Happy Birthday" by Sylvia Chidi, "A Birthday" by Christina Rossetti and "Happy Birthday to You!" by Dr. Seuss. Some birthday poems are written for specific ages, such as "Now We are Six" by A. A. Milne.
Songs about birthdays can also be used as poems, such as "Birthday Song" by Carole King and "Happy Birthday to You" by The Beatles. Three poems that were not written for birthdays, but are appropriate to use are "Happy Thought" by Robert Lewis Stevenson, "All Things Bright and Beautiful" by Cecil Frances Alexander and "Listen to the Mustn'ts" by Shel Silverstein.