I met my fiance as a peace corps volunteer. We just found out that our visa was approved

My question is what do I need to prove that I am 125% above poverty. This is the first year that my tax return will show substantial income (but may still be below poverty for the year) because I was earning WAY less than US poverty level for 3 years as a peace corps volunteer. I have been working at a full time job for the last 7 months and I earn well over poverty but because of the ammount I earned as a volunteer do I need additional proof or a co-sponsor?
thanks