Could someone please clarify what you mean by "bat drag". I think you want the hands to lead the barrel toward the contact zone but want both to get there at the same time. Does bat drag mean not getting the barrel around quickly enough?
I placed markers along your daughter's bottom hand to help you see her hand path.
This video speaks volumes regarding bat drag.
The hands don't drop, but notice how many dots are at the back shoulder as the back elbow drops to slot.
It would be interesting to see a sequence of different colored dots on the hands, back elbow and bat barrel and note their relationship to each other.
I'm sure she is not trying to drop her hands through the swing. We talked about keeping her hands up at the start of the swing and have also talked about keeping the hands tight to try and avoid casting. My guess is she's trying to keep her hands by her shoulder through the swing. I definitely see the difference, but am not sure where to go from here.