Olwen Collier planned to decorate a pub for her daughter's surprise 50th birthday party - but fell down 10 steps into the cellar and to her death.
Her daughter Allison Raymond has now called for tougher regulations after the landlords were spared jail last week and kept their licence.
Philip and Tracy Hawkins from The Stag and Pheasant, in Carmel, had 18-week sentences suspended for 12 months.
Carmarthenshire council said it hoped wider lessons could be learnt.
Mrs Raymond said her mother had gone to the pub to decorate for her surprise party, adding: "She asked Philip Hawkins where was she supposed to go. He told her just to carry on going through to the door to the right."Unbeknown to mami, she pushed on the cellar door which was left ajar and she fell, knocked her head on top of the concrete and fell 10 or 12 steps."
Mrs Raymond, now 51, said her son was behind his grandmother when she fell and tried to grab her coat.
"He had to stand there with his torch to look where mami had gone because she had just fallen into darkness.
"They rang me and that's when my world turned upside down. I went there as soon as I could and I was expecting to see her with a broken arm."
She was amazed to find her unresponsive, choking and blood coming from her mouth.
"When I arrived they still carried on serving people in the pub," she added.
"When mami was pulled out of the cellar I had customers coming around to me and looking and nosing at what was going on."
Ms Collier was taken in an air ambulance to the University Hospital of Wales in Cardiff where the family was told she suffered a fractured skull and bleeding on the brain - she died on 16 January 2023.
In court, the Hawkins were described as "broken people" following the incident, but Mrs Raymond believes their sentences were inadequate and wants them stripped of their licence.
She believes there should be changes in how pubs are run, adding: "I feel let down, there were massive failings."They can carry on now running the pub even though this tragedy has happened. This has broken our family."
The couple's solicitor Aled Owen described it as a "tragic accident" adding Carmarthenshire council "confirmed that the public house complies with all health and safety issues to the absolute best of industry standard".He added: "Mr and Mrs Hawkins accepted their fault and pleaded guilty at the first occasion.
"They had only been landlords for four months and had a successful fire inspection check on all their doors seven days before the incident happened.
"This was a tragic accident which was reviewed by health and safety officers at Carmarthenshire County Council and a number of limited suggestions were made which were adopted immediately."
He said "only in a unique and unusual combination of factors" did the accident happen. The council's head of house and public protection Jonathan Morgan said: "While we are pleased with the outcome of this extremely sad and distressing hearing, our thoughts and condolences remain with the family, who have been deeply impacted by their tragic loss of a much-loved family member."We very much hope that wider lessens will be learnt from this incident and that businesses take note of the shortcomings identified."