PS: Looking at your timeline, I am not sure if you mean your 5 year wedding anniversary. If you choose the 5 year option on USCIS form N400, please make sure that the date shown on your greencard (Permanent resident since ...) plus 5 years has passed.
Simply put, if you apply for naturalization, you can apply
- after 3 years if you got a greencard due to marriage OR
- after 5 years if you got your greencard any other way
If you apply for naturalization after being a permanent resident for 3 years, the naturalization interview will focus quite a bit on whether your marriage was real, bona-fide etc.
If you apply for naturalization after being a permanent resident for 5 years, you do not have to prove your eligibility on the basis of marriage.
Regardless of whether you got your greencard due to marriage or any other reason, if you have been a permanent resident for 5 years, claiming eligibility due to being a permanent resident for 5 years generally makes the naturalization process a bit easier (USCIS form N400, page 1, part 2, choice A is the ideal one if you can).
Take a look at USCIS form N400, you do not have to prove how you pay for your lifestyle, but rather that you paid taxes if applicable and did not break any laws.
Ted46 got a reaction from Brother Hesekiel in Naturalization due to hubby or on my own