Not sure you can simply return a firearm due to the paperwork. Maybe sell it back to the seller?
Has she shot a DE before? They are not the most ergonomic. I have medium sized man hands and mine did not fit me well.
Best option if she wants to keep it - get a 44 Mag barrel for it. I assume this will work, my DE had both the 50AE and 44Mag barrel when I sold it.