Coworker Getting Away With Blatant Time Theft While My Hours Suffer Because Of It

i have worked in a nursing home kitchen for about four months now and have been recognized by my supervisors and coworkers as a good employee. i have a coworker who started about a month after me who is extremely guilty of time theft. she comes in every SINGLE day (no exaggeration) an hour and a half before her scheduled shift. in the three months that we have worked together there has never once been a time (at least when i’m working, which is 5 days a week) that she has come in at her scheduled time. she also stays hours late, sometimes even pulling doubles and comes in on days she is not scheduled at all. when she comes in and isn’t scheduled, there is nothing for her to do because someone else who IS scheduled is doing it, so she either starts doing MY assigned tasks, or she sits in the break room or the office on the clock. when she does my tasks, i tell her to stop, and i tell my manager that i’ve asked her to stop, and she won’t, resulting in me losing hours and leaving early because my duties were finished by someone else. this has been going on for three months. i have talked to my assistant manager, manager, HR at my location, and the head of HR for our entire company. i have recorded each time there’s an issue with this coworker, i have recorded the dates and times of my conversations with supervisors, i have sent pictures of the schedules to HR so they can verify that her punch in/out times are not consistent with her schedule. today was my final straw when she came in an hour and a half early and started folding the DIRTY sanitizer rags. why the fuck is she getting paid time and a half to fold dirty rags? so i went to the head of HR AGAIN, and he told me to “be patient”. i told him i’ve been patient for 3 months. i am at my wits end here. it is blatant time theft, and i’m being less than her to do my actual job while she makes time and a half sitting in the break room clocked in on her days off. i have involved every person of authority that i can. i’m looking for other jobs, but the market is awful right now. i’m the meantime, does anyone know what i should do? btw, i live in the US