Thanks Devora for leaping to my defense :) I think that you probably said most of what I would reply to NanaNina's comments.
I think I would firstly really like to point out that I am only asking the questions, thinking, talking to people etc. It is a process that I think will take many years to feel and test to see whether it is the right thing for our family or not. I'm sure that no-one just wakes up one day with a spare room and their (grown-up) children out of the house and decide to foster or adopt? I know my children are young and I would of course wait 'til the youngest was at the very least 2 yo, if not more... but I don't think that there is anything wrong with asking questions is there? Especially from people who are alot more experienced and knowledgeable than I am. (Like yourself) But we all start somewhere, as you said. I'm not sure if I understand your great worry about my concern of 3 children dividing into 2 groups of any kind..? Three is a crowd and when there are 3 children, there often is one who is left out. My concern was that if I have 2 biological children, I wouldn't want the adopted/fostered child to be the one left out... why is that such a strange thing to be concerned about? Of course there are no guarantees, and I'm not saying I would take sides, I'm talking about how children behave to one another, not how I would behave. Children hunt in packs from what I can see... maybe my concern is not valid, but is there something wrong with being concerned about something that might happen?
Additionally, I would never consider fostering/adopting a child older than my DD. I have read enough to know that that is not advised or wise. I wouldn't want her to lose her place as the first in the family.
You also assume that I would want a very young baby because I'm asking these questions whilst my own children are young. TBH, I hadn't imagined fostering/adopting babies because I know that there are many people willing to (particularly) adopt babies. I don't know what age I feel that I would be thinking of fostering/adopting, but I certainly would not have put the youngest babies as my first priority.
I don't feel that I am very naive, but I do think that I have lots of questions and I'm learning. I want to learn from others who have gone before me, but I would appreciate being spoken to in a respectful way regardless of what your opinion is.