My Mum Recently Died Suddenly In A Nursing Home. Gps

My mum recently died suddenly in a nursing home. Gps servicing the home had been called out to my mum several times over a four week period, they had been advised by staff that mum's breathing was rattly and they were concerned mum had a chest infection but insisted there was no infection. Mum s ability to walk, eat and drink was drastically reduced then on the evening o've her death she took a fall. She was taken to her room and sat upright in her chair. Within less than 2 hours mum was dead. Paramedics could not help her. They arrived 30 minutes or so before she died and reported the decline in her heart rate, breaths and pulse. They reported they believed her death may be due to sepsis having performed a sepsis screening test and result showing her in the red zone. Can you tell me what this means please. Should I be looking to persue the Gps in court? Post mortum revealed pneumonia with pus in left lung and pulmonary embilus.