Home Assessment

Hi everyone.
Does anyone know of any caselaw or legislation that may be used to makes sure someone is given a home assessment? I ask because someone I have known for many years has been asked to an ESA assessment in 2 weeks time. She had in the past, shown 2 supporting letters from her GP saying she finds it extremely difficult to leave her home, but these were ignored and she had to attend (luckily enough, her Support Worker took he). However, she has no Support Worker or any family in the new area she has moved to. I cannot go with her as she is now so far away, and she is adamant that she just will not go. I have tried to tell her that they will sanction her, but she insists she will not be able to attend. I actually helped her with her Questionnaire, and I distinctly added in the pack that they need to respect the Mental Health Act. I am sure there is a quote from it that insists that a claimant can refuse to go to an assessment if they do not have someone with them whom they need for support. I cannot be sure, but I think the information I read said it would actually be viewed as abuse if someone in this situation was to be forced to an assessment alone. Any help will be appreciated, as I know this lady just will not go on her own.