Seeking advice from couple with the husband younger than the wife?

I have been going out with this girl for about 2 months now, we love each other, but there is a dilemma. She parent wants her to move back to her hometown. I am 23 and she is 27. She is a foreign student, and is about to graduate in a month. She had originally planned to stay here for me, but after made known the relationship to her parents, her parents is concerned with two things: 1) Our age gap, and 2) Family background. They believe that the age gap between us will cause a family wreckage in the future as we age near the menopause period, since the female will be less interested into , while the male is still very active seeking it. Due to our family background differences, they worried she won't be able to adjust to her new life easily. If you are in, or have been in a relationship, where the male is younger than the female by 3 or more years, do you think these are valid concerns from her parent's side, and what do you advise.