Adopting?

TTC RAINBOW BABY • Engaged to the Love Of My Life. ❤️
My cousin lost her daughter and she went into the court system last Friday. (She's on drugs extremely bad.) the baby is only about 6 months old but she was born three months early, and is healthy now but im worried. 
I'm going to try to get custody over her, and eventually adopt her. But my boyfriend doesn't like that because he wants us to have kids of our own.. But I just can't let her go into the system and go through what I've seen so many others go through.. I don't know how to make everyone happy right now, and if I know him like I know him, he'd come around. But I also understand where he's coming from.. But my hearts telling me what to do.