。
She studies harder than any other student.
Literal
She [topic-は] other [genitive-の] which student [to-にも] not-being-inferior studies.
他のどの学生にも劣らず is a refined comparative frame: 他のどの ('which other') exhausts the comparison set ('any other student'), and ~にも劣らず ('inferior to no one') inverts the comparison so that 'no less than' = 'as much as / more than.' 劣る ('be inferior') takes the standard of comparison with に. The classical-flavored ~ず for negation gives the sentence a slightly literary or formal feel.