Can a buyer sue me on ebay?

I put a phone for sale on ebay. Not even a minute later it was sold $175 dollars. A couple days later I printed out the shipping slip. I was on my way to the post office and I put the package in a bag. I decided to stop at the mall (right next to the post office) and go to the bathroom (I am pregnant I HAD to go). I left the bag in the stall, by the time I came back it was gone... So even though I am at a loss I give the lady a FULL refund and explain to her my situation. She is now threatening to sue me "criminally" for internet fraud and breach of contract. I am not an experienced seller on ebay and never in my wildest dream I would think someone would say that to me. I am under a lot of stress that I do not need right now. My question is can she really sue me? Shes in California, Im in Florida. Any advice would be greatly appreciated.