Expose her to the fact that the diamond industry is built upon mass psychological manipulation, and exploitation. That mossanites are both morally, and ethically better, higher quality, and less stressful to purchase. Also some cultures don't use diamond rings, they use nose piercings. Probably avoid catering if possible. Find a cheap venue. Have a small circle, mom, pops, siblings, aunts, uncles, close close friends, and grandparents. You could also just avoid the marriage ceremony all together, and just get legally married, or common law married. But if you're looking for affordable options for a societally acceptable wedding then good luck, might have to shell out at least $10,000 to $15,000 at the cheapest if you're lucky.