Ok, Im sure this has been covered somewhere else, but, can Miranda Doni short herself a die on the 1st attack and get a shield then spend the shield on the second attack to gain a die?

I thought it was a once per turn thing and you couldn't... I might be wrong though.

No it is only on one attack. Not on both.

Ok, Im sure this has been covered somewhere else, but, can Miranda Doni short herself a die on the 1st attack and get a shield then spend the shield on the second attack to gain a die?

I thought it was a once per turn thing and you couldn't... I might be wrong though.

Once per turn.

You can wait to see what happens on the first (unaltered) attack, and decide then to regen or boost on the second, but if you regen or boost the first, the second has to be unaltered.