Anything chocolate, a bubble bath with a glass of her fave bubbly and a slow full body massage.....
Be nice to her. However, real happiness has to come from within.
Make sure her house is clean. make dinner. watch her favorite movie with her. offer a back rub. Tell her she is beautiful. Ask her if she wants to go for a walk. Ask if she wants to talk about why she is sad and listen to her, respond to what she has to say, be on her side.
What's the reason? Get to her level and get to the story. A hacker always trusts another hacker.
Leave her,then come back to apologize for what you did.
if you have to ask , well.............
if she has depression u just have to be there for her tell her u love her and are there for her. When ur depressed or have depression nothing can get u out of it untill ur ready or in some cases go on meds. I no i have depression if she doesnt seem to get better over a while then u should ask her to seek some help. If shes just in a slump shell come out of it she just may need time.