How do you proceed to buy a house from a seller who appears to have significant mental health difficulties

[StrumpersPlunkett]

house is great if slightly over priced, brilliant village, but owner puts SO many constraints on viewings and on visiting today was shouting at us as we were going round because we wanted to use a tape measure, shouted because we touched the side board in the kitchen (to see if it was granite or composite)
She was SO anxious about having people in her house, she is too anxious to let the estate agent do the viewings.
I felt for her, she was shaking and verging on crying all the way round.

Not sure if there is a way of proceeding, she wants to go to her new house which is a retirement property that she has been on a waiting list for (she is only just old enough)