what are some non prescription products, drugs, or vitamins/herbs that help treat depression?

I agree with the first comment about St. Johns Wort. Here's a website that I hope helps. It has information about it :

http://nccam.nih.gov/health/stjohnswort/sjw-and-de...

Also, try talking to her about seeing a therapist and trying Cognitive Behavioral Therapy. Its pretty much the therapist and her talking, and trying to get her brain to think the proper way. I've been doing that as well as taking medication, and it helps out alot. I don't think its really right for the mom to want to put her daughter in a local institution though. If my mom insisted on that with me, it would just make me worse. I hope that helped, and I wish her the best of luck with everything. Depression isn't easy at all.

And its good to know she has a boyfriend who supports her with this also!

St John's Wort can sometimes help but it interacts with the pill. Read the instructions first.

How old is your girlfriend? Depending on her age her medical treatment may be up to her and not her mother. She should consult her doctor for the best course of action. Counselling can also be used to treat depression.

EDIT

If she's seventeen then she should be able to decide her own course of treatment, I'm not sure which State you are in maybe check it out online. I know this might be a problem if she's still living at home and her mum is making it awkward. I'm not sure how severely depressed she is but if she is diagnosed as clinically depressed then I would think she would need some treatment. I think continuing to communicate to her doctor is the best way forward, maybe the doctor can speak to her mother? Like I say, antidepressants aren't the only therapy, counselling can also help, maybe she could talk to her doctor and find out about that.