Well.... The other reviews are all true in their praise - this is a wonderful find, stylishly appointed, comfortable, close to the Underground (Putney Bridge on the District Line), and 2 minutes away from a selection of good restaurants on one side and the beautiful park of Fulham Palace and walking paths along the Thames on the other.
Proprietor Annie is welcoming and helpful, and responded to every inquiry immediately. She provides several days' of very nice breakfast things, which is such a pleasant touch, and even helped us with arrangements for a 5:15am ride to the airport!
There is one bedroom with a queen (I think) bed and a sofa bed in the sitting room which would sleep one, or perhaps two smaller children. One bathroom with a tub / shower, and also a washing machine (no dryer, use drying rack provided). The kitchen is well furnished and we made good use of it.
We found this location to be an easy tube ride into the city to see museums and theater, and going the opposite direction it is quite convenient to Kew Gardens and Hampton Court. Buses also head into the city but remember that London traffic can really be a bear! For those who want to do more extensive shopping for food and other things, a 10-minute walk across Putney Bridge takes you to Putney High Street, which has plenty to offer.
Access into the flat requires a short walk down very steep stairs (hold onto the handrail). Note that the flat is not particularly "child proofed" at least as we experienced it but I have no doubt that the proprietor would be understanding and accommodating.
My daughters and I enjoyed our stay in Pimlico. The flat is located in between the Victoria and Pimlico tube stations. The flat was nicely equipped. We were happy to have both a dishwasher and washing machine/dryer. The beds were very comfortable. The front bedroom is close to the street and there was some noise from traffic and pedestrians even though the flat is located on a quieter residential street. We would happily stay here again if we are ever lucky enough to return to London.