We were fostering to adopt a child, age 10, a few years ago. It still very emotional for me to even talk about because we really had grown to love the child. We have a bio-child who was age 2 at the time. His safety was in jeopardy, I think due to jealousy issues. The agency really should have only considered families with older children or no children for him. It was a great injustice to him. We feel like failures but had to do what's right for both kids involved. Thankfully, the child is being adopted by a family that has only older siblings. We do still have open communication with the child (can't say name -confidentiality) and hope to for years to come.
We are going to be foster parents again, when the children are considerably older. I am expecting child #2 in four weeks. I won't consider foster care until the children are at least 8 years old. We are considering in a few years doing respite care for medically fragile or younger children, although my heart has always been for older foster kids.
Fostering is hard work but is really worth it. If you don't have younger bio kids at home, I would strongly recommend it if your heart is being pushed in that direction. When you have younger biological kids and take in older foster kids, it can just get too emotional for the foster kids. Our experience was just so unfortunate.
I actually wanted to be a foster parent or adopt an older child for as long as I can remember. At first, I never really wanted my own children because I wanted to go down the foster or foster to adopt road. Please do it if it's on your heart and mind. These children really need some consistency. It takes a strong person, not just a kind-hearted person, to be able to foster.
If you are interested in more details about my personal experience, I can pm you.