I think my 6yo daughter has been depressed for the past 6 months. Inactive, misbehaving, crying spells and sensitivity. What can I do to help her?

Psychological Help. Your description is quite accurate this should be handled asap will make her and you happier meantime try to come out of it talk to her play with her can try the school psychologist but it would be better if you could get private most incl medicade cover this treatment (abomacare) until you can talk to her about it she may be able to tell you what is bothering but get help.
Check school first. There may have been a precipitating episode at home or at school that has upset your daughter.. Start by asking her teacher if she has noticed a change in your daughter at school or with her friends.Then you might talk to your daughter and see if she will confide in you. If nothing helps seek help from a professional.