First Potential Match - questions

Hi all - Would appreciate any input and/or advice. Our assessment to adopt from foster care was complete and approved just under two weeks ago. We were just sent our first potential match - two sisters that are 10 and 4. The older sister seems to have PTSD but otherwise seems to be doing well. She doesn't have any developmental or learning delays so we don't really have any concerns about her. We see some red flags about the younger sister which is where the bulk of my questions are. She tested positive at birth for drugs - there is some conflicting information about which ones but it seems like at least cocaine and THC. She apparently shows some agressive behaviors, has a speech delay, and it seems like she may have a learning delay as well. A therapist during their first visit diagnosed her with ADHD and Conduct Disorder Childhood Onset Type. This is where the bulk of my concerns come in. The caseworker reports that she just has normal age appropriate tantrums but from what I've read about Conduct Disorder it is much more serious than that and that's not something I'm sure I'm equipped to deal with. The birth mother apparently has a history of ADHD, Bi-Polar, and Depression which I believe from what I've read may increase the chance of conduct disorder. Does anyone have any experience with this issue? If so, I'd love to hear about it. Thanks in advance!