While I was refunded by Jenny within a few days of my reservation, this was a very unfortunate experience. Our correspondence was however very polite and informative before and right after making the reservation. She was very upfront with me that the last guests had an issue using her keys and that they were being refunded. Jenny assured me that the person who I would get the keys from had two sets, and she even gave me her Super's phone number in case there was a problem. She also said we could check in any time during the day.
When I did call, email, and text the person for the keys, I received no response and actually never heard any response from this person. I then contacted the Super who had no idea who I was talking about, and additionally there had been no apt # listed on the confirmation for me to reference. I had booked the apt for my mother and aunt who were driving through NY from FL to Boston. We didn't get a response until much later in the evening, at which point I had already sent my mother and aunt on their way back to Boston since we had nowhere for them to stay.
While Jenny was very nice, it seems her listing isn't very well thought out or organized for the guest. I might suggest that she keep her keys with a local business that is open 24 hrs, like a bodega or diner.