The only case that had specifically considered what "unlawfully" meant in the context of abortion was a 1938 English case heard in the Courts of Assize, Rex v Bourne. In that case, Dr Bourne was charged with the crime of abortion under section 58 of the Offences Against The Person Act 1861 (the same section on which the Victorian law drew).
The only instance that had explicitly looked into what "illegally" meant in relation to termination was a 1938 English case heard in the Courts of Assize, Rex v Bourne. In this case, Dr Bourne was charged with the crime of abortion under section 58 of the Offences Against The Person Act 1861.