Betty Guy of Johnstown, Pembrokeshire, died in November 2011.
Her daughter Penelope John, 50, of St Dogmaels and grandson Barry Rogers, 32, of Fishguard, were arrested earlier this month.
The pair appeared at Swansea Crown Court on Friday and were remanded in custody ahead of the next hearing in October.
While pleas were not entered, a date of January 2018 was laid down for the start of a three week trial.
Relatives of an 84-year-old woman have appeared in court accused of her murder seven years ago.