I say non-issue, since there is a far more extreme example from 120 years ago. Frances Folsom was 22 when she married Grover Cleveland and became first lady. She proved to be a very popular first lady. And even Cleveland's political opponents admitted that she was very easy on the eyes.
President Tyler had a young wife too...twenty-something in the 1840's. He was much older, I think more than twice her age at that time.