You are doing a great job keeping her settled by the sounds of it. Fantastic idea with imbolising her arm but I would hold out giving her panadol. Sometimes it can mask pain/injuries. It can be hard to sit there and not give her anything but it could be a good idea so the dr's can assess her fully. Call the ER and ask them what they think and if it is okay to give her panadol or not.
Another idea is if you really concerned about DD have you thought of calling an ambulance for them to assess her and take you and her to the hospital?
Good luck and please let us know how you get on. We'll be thinking about you.