If the owner has been dead a year and title was never passed to any heirs, then it is likely the owner died without a joint tenant on title or a will or trust. It is likely the daughter/tenant did not pay the mortgage because a clear title was never passed to him/her and his/her siblings because the owner died intestate. Perhaps there was not enough $$ and/or too much debt in the estate which would have eaten all the equity of that property so no one opened probate. It’s also possible that none of the potential heirs had the capacity to pay the mortgage or the decedent borrowed more on the property then it was worth so they declined to. The person you see living was probably just trying to live for “free” as long as possible until the lender took it back.

If that property is/was sold to a private party on the steps, that party has the right to extend a written lease to the occupant or evict them, whichever they prefer. If the lender takes the property back, it has the same rights but will most likely evict the tenant and market the property because there is a shortage of SFR’s in that zip code for sale.

Do you know what the opening bid was at the trustees sales and whether it was a first or second TD foreclosing?