I don't trust Mom's new personal care worker. Any advice?

Mom is in a Nursing Home and will have a new personal care worker starting on afternoon shift this week. I had a run-in with this person about four years ago when mom first moved into the home. She was showering mom and I was across the hall in her room. I heard mom screaming and then understood from mom's behavior that the worker was being rough with her because she was being uncooperative. I put in a complaint about her, but it never went anywhere. Now she is back to haunt me and I am afraid of mom being manhandled by this women. I also had suspicions that this same women stole mom's watch and ring and two leather handbags. No proof, but I know it was her. What can I do but worry about what hasn't happened yet. Of all the nice people who work there, why did she have to get the job? I have been giving mom a shower once a week so I don't have to worry about that at least.