Because women tend to live longer than men, it makes more sense for a woman to marry someone a few years younger. She'll spend less time alone in her senior years. DF & DM were only 3 years apart (he was older) but she still spent 5 years alone.
MY SIL is married to someone 17 years older. It din't make a difference until he retired, and she continued working. Her job required a lot of foreign travel, and he was pretty awful (IMO) about it. She took an early retirement last year. He also expects her to act older, ie take an afternoon nap because he does, go to bed early because he does, etc.
I dated someone 17 years older than I when I was 20-24. He died of pneumonia a few years ago. I would have been a widow in my early 50s had we married!
DH is 5 years older than I, and he fully expects to die before me. Of course, his father felt the same way, but his wife died 21 years before he did.
So, follow your heart, but know that the golden years may not be so golden if there is a huge age difference. I watched my parents go from alert, vital, active people to totally dependent invalids who died in less than 5 years.