Hi, Welcome to HCM, I am Dr. Das
When an aged patient has gastric ulcer every doctor will search for any associated other disease like H.pylori. It is quite normal.
But what seems very odd to me is, the condition of your mother needs very close observation and resuscitation
with compensating the bleeding and vomiting
and low potassium level which may get very serious at times. And after stabilizing the patient then planning for these investigations will be necessary.