Anemia after Blood Transfusion? Body?

My Grandmaa got Anemic due to bloodloss due to small Holes in Stomach which r formed due to Wrong medications ..(she suddenly got mild paralysis..we admitted her in hospital..treated & found Holes due to which blood loss occurred) ..But now she underwent a small surgery for Holes in Digestive system everything is fine with Holes closed and after the surgery 3 blood packets were transfused ..her hemoglobin count is 10.6..Every thing is fine upto for 2months or so ..no prob But now Suddenly her hemoglobin is dropped to 7.5 in 15 days..may be again holes in stomach ? Or I read from internet that transfused blood lifespan is only 55-60 days so that blood may be dead and she is fine nothing to worry and now this is her blood in her body ? Note- she had mild liver syrrosis and enlarged spleen but doctors said no problem and gave meds..she takes them daily..Pls help to resolve my doubts thanku sir