Question

Jill also orders a ____ to help keep her legs properly positioned.

Answer 1

Jill also orders a "Footrest" to help keep her legs properly positioned.

Usually people who are working in an office or spend most of their time on front of a computer screen complain about  back ache etc. a reason is that their legs are not positioned properly which causes strain and aches in the body. A footrest helps that position to maintain a proper posture avoiding pain etc.