I see no reason to do an amnio. Your daughter appears to carry the two thalassemia genes from the parents, both beta thal minor and HbD thal. The high HbF of 6% is typical for beta thal minor. The HbA2 level is normal and not usually seen with thal minors, where it is higher, as in your wife (5%). This is due to the effect of the HbD, which masks the presence of thal minor, but in this case, the HbF level is what would be expected if beta minor is present. The presence of HbA in your daughter shows that her beta gene cannot be zero, because the gene she received from you produces HbD and no HbA, so her HbA production has to come from the mother's gene, which means it has to be beta plus and not beta zero. Interestingly, since I last posted on this topic, we have a new member who does have HbD beta zero thal and still carries a good Hb level without transfusion. The HbD compensates for HbA, but it does break down sooner, sometimes causing some enlargement of the spleen. This is unlikely to be much, if any problem for your daughter. Your daughter already has the defective genes from each parent without any problem other than very mild anemia and any other children should be no worse.
I had previously mentioned that Hb lepore is sometimes seen with HbD, but there is no mention of any other hemoglobin variants in the tests, and there would be no HbA present if your daughter carried the lepore variation, so this seems impossible in this case.