Finacee or Dependent Visa Requirements

I (Age 27) am from India currently residing and working in USA and my fiancée (Girl Friend, Age 21) is from India currently residing and working in India. I want to get married ASAP since I have already delayed it by two years. I am thinking of this weird scenario of migrating to UK from the US. I want to avoid going to India and rather thought of getting married outside India due to my current job, global recession and personal/financial circumstances. Hopefully UK will work out. I do qualify for the Tier 1 visa since I have a masters degree from the US and an annual income of more than 45000 UK Pounds. I do have enough money in my bank account in USA to support the dependent.

How do I prove my relation with my Fiancée (Girl Friend), What documents would I need to submit with the dependent application.

I just have the following:
1. Few casual pictures of us together,
2. Emails,
3. Letters,
4. 3 month old common (Shared) bank account in India (Account has Indian money equal to 100 UK pounds only)

Please help me in identifiying what more I need to get married to my GF ASAP. I don't want my girl friend's application to get rejected, I know there is no problem with my application.

Thanks for your help in advance.