Not sure about this, the memory is failing, but…
I am pretty certain that a settlement deed is usually used as a vehicle to reduce exposure to capital gains or inheritance tax.
I think…. A trust can be a sub-species of a settlment but not the other way around and that, generally, a settlement operates as a trust.
Conjecture on my part – your claimant is either the beneficiary of a trust or a beneficial owner of the property. – The parents have “gifted” an interest in the property to their daughter.
As well as getting a copy of the deed paperwork you should also look at how the parents purchased the property and who the vendor was. I’m even less sure about this bit but the daughter could have gifted it to her parents and sought to maintain control. To do this legitimately she would then have to pay the full market rent but, hey, why not if it will be met by HB!