Hi Jen, you poor thing hun..but like Lea said I'm sure she will be fine. Please don't be upset with yourself..
If she is reluctant to move her arm, she may quite possibly have a 'Pulled Elbow'..have you heard of that before? Quite common in toddlers, but that may be what has happened. I would give her some neurofen too when she wakes, and then maybe someone else can take you down to see a doctor so they can have a look. They can have a feel of her arm and see if anything has popped out of place which can happen with kids joints (I may be completely way off track! just offering a possibility). Or maybe it just got stretched a bit and is just still a bit tender.

The great thing is, kids are soo tough and recover so quickly! I'm sure it will all be fine, but I would get it checked out.