Feedback is up to you. I think that since the seller was particularly difficult, she deserves whatever feedback you give. Not only didn't she accept your return, she argued with you, accused you of damaging the bag, and ebay was required to step in to ensure you got your refund. I'm sure she got a defect on her account.
Here is one possible scenario. The seller decided to refund you but only had some of the money in her paypal account and the rest was in her bank account. The money from the bank account could take several days. Personally I think this is a bad practice. I always keep enough money in Paypal to cover any possible disputes until I either receive feedback from buyers or a few weeks have passed. I really doubt this is what happened though, because if the seller had planned on giving you a full refund she wouldn't have escalated the case. If she had agreed to the return, she would have just checked a box, which would have given you a return label. Then when she got the return back, she would have checked another box to release your refund.
Did you return the bag? Did ebay give you a return label?