14 Years Old (Because she was 14 at the time of making the wish, she is eternally 14 years old)

14 Years Old (Because Madoka's soul is inside of Ultimate Madoka, and after Homura separated it from Ultimate Madoka, it was still 14)

14 Years Old (Other, please comment below)

13.772 Billion Years Old (Because Ultimate Madoka has existed for that long, and conversed with many girls, such that she should have matured since her initial conception)

13.772 Billion Years Old (Because Ultimate Madoka's physical body would be that age)

13.772 Billion Years Old (Other, please comment below)

N/A (The idea of applying ages to a concept such as God seems silly to me)

N/A (The idea of applying ages to a force of the universe such as gravity or magnetism seems silly to me)