Question about adopting a child in CPS custody

[FONT="Garamond"][/FONT] I am new to this site, and have a unique situation. My ex-sister in law has an 11 month old little girl who was removed from her home by CPS due to her drug use. This baby is not my niece. The baby's father is in prison for the next 25 years w/o possibility of parole. She was initially placed with a foster family, and then after several weeks was placed with a single uncle on the father's side. My ex-sister in law contacted me last week to find out if we would be interested in adopting the baby. She is aware that my husband and I want to one day adopt a baby. I do not know if the uncle is interested in keeping the baby or not. The mom believes that she has the right to choose who adopts her baby. I honestly don't know how all of this works. I have contacted an attorney and he is working to contact her court ordered attorney and CPS caseworker to get details about the case and the child. I am just curious if anyone has any experience with this type of situation. Any information would be greatly appreciated.