Shanna: The Firehair (Shanna: The Firehair #1)

In the hidden underground world of Evana, a young girl, separated from her true family, has been adopted by natives and grown up among them as Shanna the Firehair. But while she is used to the jungle's dangers, Shanna now finds herself faced with the unfamiliar and possibly fatal arrival of mysterious aliens, one of whom possesses her adoptive father!