She is the daughter of Ellissa Marble-Brook and her girlfriend Joanne Wilson.
Eddie created her on the OCCT machine with assistance by Snow/Flake.
So she wanted a friend so, Eddie made a girl for her to play and Snow/Flake wanted her to be like her so, another head was added.
Ellissa was told to have a new daughter and the transfer was made but, Eddie forgot to tell Ellissa of the detail of the two heads so when she came next day to pick up Pepper she asked "Which one is Pepper?"
And resulted in her giving Eddie a thick ear. ^^' but, Peppers pretty blue eyes made her "mothers" heart melt and accept her new daughter.
As far as Pepper knows, Ellissa is her birth mother. and her older brother being Kevin the rabbit.
She is listed as conjoined twins so not to arise arousal.
And of course, they still need to explain it to the boyfriend of Joanne and Ellissa about Pepper
Pepper [c] *WhippetWild
I do not know how tall Pepper will grow to be but her mother is 26ft 0 tall and Joanne being 19ft tall.