Her parents are Dutch and they moved to Australia when Inge was four
years old.
Hornstra has two children, a daughter, Summer (born 12 July, 2004) and a son, Javi (born 2008).
She still has contact with her former Heartbreak High (1994) co-stars, especially with Vince Poletto (ex-Matt). She already knew him from the school of acting and says he is now her best friend.
She graduated from Australia's National Institute of Dramatic Art (NIDA), with a degree in Performing Arts (Acting) in 1994. Among the graduates was her future McLeod's Daughters (2001) co-star, Bridie Carter.