You know, I'm not sure. I don't know if it would leave any remnants behind or not. I had one once, didn't burst, but by the time I had the u/s it was gone altogether.
I think I would go with what the ER said and then if she continues to have pain for several more days, she should see her reg. doc. Maybe the ER was too busy, or thought it wasn't their job to try and figure out what it was....you never know.