Right to reside

Would welcome thoughts/suggestions on this one:

73 year old Icelandic national; she came to UK in 2002 and lived with a man for a few years, they were not married and she has no contact with him now. She did not work then. She states she worked as self employed from 2007-2011 but was not registered with HMRC and she has no other evidence of this work. Since 2011 she has been living on money inherited from her mother.

She is now homeless and living in a local authority hostel. HB is in payment - it isn’t clear if the Benefits Section have actually considered right to reside at all.

She claimed PC Guarantee in December and has just received the decision that she has no right to reside.

In the absence of any better ideas, I would have thought the most promising route is permanent residence due to the 3 years residence as a self-employed worker ending on a date after retirement age.

Even if there are no payslips or tax documents, there must surely be some evidence of her self-employment during this period. What about bank statements, loan applications, statements from old customers, professional memberships etc. Even if tax was deliberately avoided, the work could be sufficient to create a right to reside.