If a person has a little higher than normal hgb f result, but no symptoms, does that confirm thalassemia b minor? No sickle cell in the family.

No. . Beta thalassemia would be suggested by an elevated HGB a2. There are many different genetic abnormalities that cause thalassemia. Some may increase HGB f, though this is not the norm. Also, thalassemia causes small red blood cells and an related red blood cell count with variable degrees of anemia due to low hemoglobin.
No. Babies have higher featal hg, also some drugs cause increase fetal hemoglobin, some genetic condition called persistant fetal hemoglobin can cause this---sickle cell trait without sickle cell anemia have higher hg f---need more evaluation---you see it has several causes, and need quantitation.