Vomit and sleepiness elderly. For life?

My 79 year old diabetic mother on medications of aspirin, diabetic medicine, calcium,cholesterol reducing tablets and urine control medications occasionally keeps complaining of throat side pain .She was already taking antacid once a day and sometimes digestive syrup.Two.days back she had 3 vomitings with black colour in one and green in other . Post this she was seen shivering.No fever is there We are since then giving her extra antacid and light frequent food to consume .Shivering is stopped but she is sleeping more than usual.What is the reason and what tests to.be done.?Could it be ulcer in throat or simple GERD caused vomit? Should we be concerned for her above normal sleep routine now? Also guide if low dose aspirin and cholesterol once started in elderly can it be stopped or worth continuing for life?