She is listed as Elizabeth Warden on her daughter Mary Jane's birth certificate and on her daughter Edna's marriage.  Her marriage to Samuel states her parents were Phillip and Elizabeth Warden.  I have also seen her named Elizabeth Richlings which is quite close to how her mother's surname is spelled on the 1901 census.  Did Elizabeth have a step father and often used his name?

The 1901 census shows a step daughter for Samuel, Lila Patterson which would lead me to believe Elizabeth was married previously.