Tanya comes from the name Tatiana and it means queen of the fairies.
My sister was crying when my parents brought me home from the hospital because she wanted a brother, so they said if she would be happy and like me she could name me. They had given her a book about new babies to prepare her and in the book the new baby's name was 'Tanya'. There you go... they also didn't bother to give me, or my sister, a middle name.
My daughter's name is Rowan, which is a tree in Ireland with red berries. Some books and websites have given meanings such as little red head, red headed, or just the colour red (she has red hair too!) but mostly everything just refers back to the Rowan tree. It has ties with dragons in the old stories and legends. I think it's rather neat.