I have no experience with it, so I'm sure I won't be of much help, but I figured since nobody else has replied, I might as well give my input. LOL
Of course the most important thing is to just be there for her when she needs you. Remind her that she's not alone, that you'll always be there for her, etc. If she seems to be a bit depressed, little compliments don't hurt, just something as simple as telling someone that you like their hair or outfit or something is a great mood boost!
If Adrianna is in therapy, maybe you could tag along to some of the appointments and just duck in for the last 5 mins or so, and you can ask a few questions about what you can do to help and such.