How can i help my friend with depression?

My friend has depression really bad, it runs in the family... and i would really like to give her some advice about it...but she wont tell her family because they wont believe her so she cant get professional help with it...she is always pessimistic even though she tries to be optimistic, she just cant and she is always upset and just cant seem to be happy, its been like this for about two years and last summer when someone close to her died, it got extremely bad...do you know of anything i can tell her to do that will make her depression better besides therapy and medication?