Still Waters is in Hoveton, Norfolk. It's a detached house right on the water, with its own private mooring.
It sleeps eight people. There are four bedrooms and four bathrooms, so everyone gets their own space. It's a 4 Star place, which means it's comfortable and well kitted out. The stairs are mentioned as being open, steep, spiral, or narrow. I'd just check the photos to see what suits you.
You get the garden to yourselves, which goes down to the river. There's a private 8-seater motor launch you can use to explore, but you need to arrange that with the owner and there's an extra charge. It's handy if you want to get out on the water without hiring a boat separately.
Wroxham is a few minutes away. They call it the capital of the Broads. There are shops, cafes, and a few places to eat by the water. The coast is about twelve miles if you fancy a beach day. Norwich is only eight miles away for a proper day out, with the cathedral, shops, and that.
For things to do locally, there's boat hire, walking, and cycling. The National Trust has a couple of big houses nearby: Felbrigg Hall and Blickling Hall.
Facilities: it's got pretty much everything. Washing machine, dishwasher, WiFi, TV, parking. Bedding and towels are included. You can bring up to two pets. There's a cot and highchair if you need them.