First of all, I think your way of thinking and your reasons are right on track. I also think it's great that you are preparing now for when you turn 21. I have to tell you that, while there are some white toddler girls around I have not seen many without health and/or behavior problems because of what they have been through, or are part of a sibling group. Also, the wait may be longer for you because not every child can do well with a single dad - some need 2 parents due to needs.
And yes, disability is generally accepted as a form of income. As far as age, the ages that are considered toddler are 1 to 3. Also, don't hold yourself to age 21, because if you want or need to do something else with your life at that point you'll be torn. Adoption isn't something that should tear you up. It should feel right.
My advice for you - get a good parenting class and be realistic, no matter how much it hurts. My husband and I had to reject a sibling group that was offered to us, and we cried over it for weeks but we already had a child placed with us on an emergency basis and couldn't take them because they couldn't be around other children. We have since adopted that child and his brother and are happier than we have ever been, and the boys are flourishing!
Good luck, and I hope you find what you're looking for.
