I think i know my home assessor. what can i do?

I live in a small village and am in the process of changing over from DLA to PIP. Capita have given me a time and date for their health professional to come and visit me at home for my interview. There is just one problem. Im pretty sure since i live in such an isolated area the assessor they will send me is a lady who works for Capita doing these assessments in the next village and since my grown up son and her daughter were in a relationship that ended badly we are not on the best terms.
If they send me this lady to assess me, i am terrified it will eb a conflict of interest and she may let her personal dislike of me and my family affect her decision. Even worse, i dont wish any local knowing about my personal health problems.

Can i ring up Capita Enquiry center and ask the name of the professional they will be sending me and if its her can i explain i feel their is a conflict of interest as we are known to each other and ask for someone else? Will they give me this choice? Very very worried as its hard enough to be treated fairly as it is without worrying my assessor may still be harboring a grudge against me for a family matter.

Any advice for me? Thank you so much

Thanks Gordon. But what i really want to know is will they accept that? Obviously the only way to know is to ring Capita which i will do when they're in the office tomorrow morning but in the meantime, im having a bit of a melt down worrying that they may not see this as an issue.