Kathrine's is a great house - very spacious - which is such a luxury when you're on holiday. We enjoyed exploring Brooklyn from the house, and there are great places nearby to entertain young children. There was a 3 and 5 yr old in our group and they loved the water play areas in Brooklyn Bridge Park and Prospect Park. It is also well connected to Manhattan - we had friends in the Upper West Side and it was so easy to get there.
The house is probably perfect for 4, and a worthwhile indulgence for 2 (which we were for a few days). However our group of 6 was happy with the set up.
We didn't meet Kathrine, but she left good and helpful instructions.
We'd definitely return if we have the chance.