My husband and I recently began discussing sibling adoption, but on a much smaller scale
We went from one child to considering 3. My husband was in shock when we were first approached by DFCS. After we sat down and talked about it, our family "goal" had always been a family of four. We just planned on adopting a second child sometime in the future. We just kind of came to the conclusion, "what is one more?" Unfortunately the children are being left in the group home but we knew we were up to the challenge!
In your case if you looked at the situation as opposite from where you began, 6 children and then considering a separate 7th child, "what is one more?".
As long as your house is large enough and your washer and dryer hold out long enough, I guess your biggest concern
would be the purchase of a ten passenger van.
Good luck and God Bless.