Jo has been a wonderful host. Even though I was booking pretty much at the last minute and had only difficult Wi-Fi access, she was very helpful in sending me directions to her apartment.
The apartment is litteraly on the block off the Copacabana beach. It is protected by a guardian and she gave me a key to the apartment right away so I could come and go as I pleased.
My room was fairly large with a two-people bed, a wardrobe, a TV and two chairs. Besides, you have a large window to look out to the beach. I think you share the bathroom with the family (we never had any time conflict so I'm not sure). The bathroom may not be the most modern, but it all worked without problems and hot water in the shower worked as well.
Her family (husband and son) were very nice. Since I hardly speak Portuguese and they only speak little English, we communicated mainly only the basics. Nevertheless, they were always very helpful indicating the closest public transport stations and most practical bus numbers. We also used Google Translate a few times.
It is not at all noisy at the apartment.
I can fully recommend it to anyone staying at the Copacabana. It's perfectly located, it's a very nice family (the dog Fiona as well) and I had a great time.