Irina's place was one of the best places I rented while in London! First of all, Irina is an absolute gem. She went out of her way to accommodate me when I asked for her place on a day she wasn't necessarily available to check in. She made changes to her plans to make sure I was able to check in on the day I wanted. Since I had the place for a couple of months, she messaged periodically to make sure I was ok and comfortable. Overall, Irina is a wonderful host and her place is so beautiful, well taken care of, and very convenient!
Flat: the flat is spacious for a one-bedroom with windows and a balcony. It's quaint and delightful. It's located in a quiet residential area and is very well-kept. The wifi connection is SOLID! This was so important for me as I work from home and was in London on a work assignment.
Location: So, admittedly Wandsworth is not the closest to the city. That being said, you have access to Uber Boat, Wandsworth Town (train), East Putney (tube - district (green) line), and a bus around the corner from the flat that takes you to Putney Bridge station (tube - district (green) line). You're surrounded by parks and the borough is quiet and delightful to walk in.
The only little thing I recommend because of the location: on your check-out day, if you have a lot of bags (so if you're doing a short/long-term stay with multiple luggage), book a taxi in advance. Uber drivers in the UK in general are just not reliable.