The THV do sleep 9 but you will be on top of each other. They are small 3 bedroom units and have no more living space or bathrooms than the 2 bedrooms. The master bedroom has a queen, the 2nd bedroom has a full sized bed and the 3rd bedroom has bunk beds. In the living area, there is a sleeper sofa and a sleeper chair. When the sleeper sofa is open, it takes up the entire living area.
There are 2 bathrooms, a gorgeous one in the master bedroom. You have to walk around the bed to get to it which makes it inconvenient after everyone goes to bed. The other bathroom is by the 2nd and 3rd bedrooms and it's a small bathroom but it does have full amenities.
There is only parking for one vehicle per villa and using WDW transportation is cumbersome here; you either have to trek to SSR or take an internal bus and then change buses at SSR. Many people love the THV; we did not.
There are also grand villas that sleep 9 at other
DVC resorts. We stayed in one at Kidani a few months ago and it's amazing. It has 3 bedrooms and 4 bathrooms. The grand villas are bigger than the THV villas but the cost will also be quite a bit more. There are grand villas at many of the DVC resorts but they are hard to get unless you own at that particular resort.
You could sleep 9 in a 2 bedroom at OKW, AKV and BLT. They have one master with a king, the 2nd bedroom will have 2 queens or a queen and a sleeper sofa. There will be a sleeper sofa and sleeper chair in the living area. The OKW 2 bedrooms are bigger than the THV and any other 2 bedroom DVC units.