The master bathroom is split with a sink and tub in one space and sink, toilet and shower in the other. THV has three bedrooms, but one bedroom is a set of bunk beds with bunk sized mattresses (smaller than twin sized). That might work for the two younger kids depending how tall the 10 yr old is.OKW has the largest 2 BRs, and they sleep nine. It only has two bathrooms, though, which might be fine for you depending on the family members going.
I had 7 (3 adults and 4 kids) in 2 bedrooms at kidani and bay lake. It was too many people for kidani, the villa just wasn’t big enough. We had plenty of space at bay lake.
From what I can see, they are both 1152 square feet. OKW is hands down the largest of all 2 bedrooms at 1395 square feet.I always thought Kidani had the larger rooms of the two?
We did kidani. It had 2 queens with own bathroom for one bedroom. Another bedroom with a king and full bathroom and then a double(?) size pull out in livingroom to sleep two as well as a pull out sofa chair that can sleep 1 as well. For the life of me I can’t recall another bathroom.
Living room area, kitchen with counter that had and several seats, eating area table which had a bench and chairs.
Love the resort ( tho Jambo is still a favorite).
It really depends on privacy needs and comforts required. Only you know what your group can work with. We had extended family in 2 other rooms. Same floor but not next to each other.
Best of luck wherever you go. Nothing like making Big gathering memories. Enjoy!

You definitely need kids for the THV to work, unless you have short adults who can fit in those bunk beds in the third bedroom. They are shorter and narrower than twin beds.Treehouse villas would be my choice for most space. That is what we did. However we had 4 adults and 6 kids (3 teenage girls, 2 younger kids and one under 3). Fantastic place and one of the reasons (besides location, spa, golf, Disney springs, etc) that we purchased SSR, knowing that we would bring other than the 5 of us to Disney. Added bonus is you can grill just outside your door (or steps).