Leesa Stevans

I am a thirty nine year old single mother of two and am researching my family name of Stevans and Bowyer,My Grandparents are now deceased as well as my mother and i do not know very much about anything relating to origins or history of the family or names as i was bought up in an orphanage in Ballarat Vitoria Australia.I do know that the Bowyer name is in Newzealand as that is were my grandmother was born and that Stevans and her married, Stevans Father was born on the high seas on his way to australia and that most of the Stevanses changed the spelling to Stevens using an E instead of an A.The name Murfett is my sons fathers name does anyone know its origins?.