Carer inappropriately touching Mum. It may be nothing - can I have some advice please?

Recently, a new female carer started work at my parents’ NH. Lately I have noticed, on a few occasions, that when she needs to help my mum sit down or maneuver her out of the way, she places her hand on my mum’s breasts. My mum is non the wiser, being in late stages Alzheimer’s but I know if she was herself she wouldn’t want to be handled that way and would want to be treated with more respect ie by the carer touching her hands, elbows, shoulders etc. I haven’t said anything yet because the carer is Eastern European and I know that things are different in their culture and maybe she sees nothing wrong in this. I don’t want to get her into trouble but at the same time, I don’t want her to handle my mum this way. Do I speak to her? Do I speak to the Head Carer? Do I do nothing? Mum isn’t upset by it but I am.