How to set up bedrooms?

3 bedroom house. Two larger bedrooms and one small bedroom that only really fits a full size bed and dresser.

7 year old boy (sorry, I should have added he has autism, that’s why we don’t want to put him downstairs)

4 year old girl

Won’t find out gender of this baby until birth (April)

We have a finished basement but don’t feel comfortable putting our 7 year old down there and we don’t want to be on a different level of the house from the kids.

We’re thinking put the 7 year old in the smallest room, 4 year old will share room with baby (will stay in our room until 1 year)

Is this the best option regardless of gender of our third?