This sounds like an aural hematoma. It is caused by heaad shaking or scratching at her ear.
If nothing is done the body will reabsorb the fluid but the ear can be deformed looking permanently like a califlour ear of a boxer.You do not have to treat that.
However, if it is swollen ,you can apply hot compresses if it is an abscess to get it to drain.But nothing will happen if it is a hematoma.
She may have one to two mg of benedryl for every lb of her weight - every 8 hours if she is uncomfortable.
Please let me know if you still have questions and how your girl is feeling. I will be here all week and happy to help further
I hope she will be fine.
Sincerest best wishes,