Looking for advice

Hi, My husband and I are in the process of adopting a baby boy. He has been in our home for 5 months now and we are just waiting out the six month period before it all becomes legal. We also have a 6 year old. Our family has been so blessed with the new addition of our second son 5 months ago. We have really been struggling with the BM. Being adopted myself, I want to be sensitive to her and want to appreciate what she has and is currently going through. I don't want to come across as being insensitive and unappreciative to what she has done. But at times we really feel like she is trying to take advantage of us. We feel that she sees us as "caregivers" to our son, and not parents. We are unsure of how to deal with her, because we want to be sensitive and not add to her grief process, but we also are parents of two boys and have to think of them. If anyone has any advice, it is welcome. Thanks