As a momma to seven.....I can tell you that the most we have ever had at home at one time have been five children.
We live in a four bedroom home, with a large 'extra type' living room too. (It's an old home with odd rooms....but it works.
).
Anyway....I'm a firm believer of having your baby in your room for some time. I think this only helps for the other children to sleep better during the night (night feedings)...but also helps in the bonding area.
Our two boys (13 and 10yrs) share a bedroom, and for the most part, always have. (Adopted at 3 and 6yrs). It's a larger room with a divider down the middle half way up to the ceiling. I think it's a good thing, as it forces them to get along with each other.
For our first two babies....we had them in the same room since day one. (This was many years ago). One of each gender, they continued to share a bedroom (we lived in other homes across the country) which went from: one with a bed, the other in the crib, to bunkbeds later on. It worked well, and we 'separated them' at around 3 and 5yrs ....only because we had just moved into a newly built home at the time.
In regards to what the agency thinks. This can go either way. It's been our personal experience, that to adopt privately, the agencies have been more lenient with this kind of thing, than when we 'went through the system to adopt'.
I think sharing a room is a really good thing, because it forces kids to share, compromise and often comfort each other when they think parents can't understand.
One point though in my opinion. We live in the country with a huge yard and 34acres of trees and pastures. When anyone needs to be alone, there is a lot of room. If we lived in the city, the need to have one's own room might be a different thing in regards to having more space to him/herself, you know?
Best of luck. We're hoping for one more baby before we're done.
Sincerely,
Linny