The best advice I can offer is to try and be a friend, not a therapist.
If the difference seems confusing? Consider if she was dyslexic or diabetic. A friend might listen to venting about either, be a shoulder to lean on from time to time, or give a shout when something seems extra wrong... but they’re not going to try and teach them how to read, or be attempting to monitor their diet or insulin use... and if all their time together is spent discussing or dealing with dyslexia or diabetes? That’s not really a friendship, is it? That’s being a special needs tutor or endocrinologist.
Friendship is an invaluable thing, but people often don’t weigh it accordingly, thinking they need to do more because they love this person. Attempting to be more than a friend? Will exhaust you, and unbalance the relationship. That’s why even endocrinologists, teachers, & therapists refer their loved ones to colleagues... rather than trying to be all things, they choose the most important role. Which is the personal one, rather than the professional one.