hi Haldashti,
i would only advice you to put in as many proof of relationship such as outings photos, hotel accomodation bills if u have lived in together, letters, emails, phone bills, skype, facebook chats, whatsapp,bbm chats, dhl fedex gift waybills showing stamps of countries. PCC certficates for any country she lived for more than 6 months, exit and entry stamps, boarding passes, visas, wedding bills, mainly engaement ceremony pics, wedding ceremony pics..
wedding certificate attested by concerned ministries..