If you dont ask her out you wont know if the age is a problem, she could be very mature for her age.
The question from me is,"Does her age concern you or is it more of a case of how society will perceive it"?
My friend is 35 his wife is 51 this year they have been married since he was 20 and very happily so, some will think eww others think nothing of it.
they have had their problems with running their own band for sign ups because of her age but he turns them away and remains faithful to her
Age IMO is not a factor as long as its with mature people who know their own minds.
A mistake is always forgivable, rarely excusable and always unacceptable.
Robert Fripp