I have a fourth way to add...
in reply to a message by Cassandra113
Besides TAM-uh-ruh, tah-MAR-uh, and TAM-ruh, I have also heard tah-MAIR-uh...I would avoid this name just because of how many different prns there are. I use all four. I always try to find out how the girl says her name before I call her anything, but most girls I know go by Tam or Tammy anyway. My cousin (who is tah-MAIR-uh) goes by Tammy, my best friend's sister (TAM-ruh) goes by Tammy also, and another friend I have (TAM-uh-ruh) goes by Tam.