From what I see I lean towards not genuine, HOWEVER, maybe it was cleaned in such a way to make it look unnatural. Basically saying, it's always worth taking such pieces to be examined in person by a coin expert. There have been cases where certain coins have been assumed to be fakes and were later proven to be genuine.
I haven't seen the coin in person so I can't comment on the actual look/feel. I do have my doubts about its authenticity based on the photo she sent me. That being said, the story on how the coin was found is interesting. It was found by accident while digging a hole for a plant in the backyard of a house built in the early 1700's. I'll ask for more pictures tomorrow.