Apparently, young-ish applicants from Nigeria are sort of a thing. I vaguely remembered a similar situation from several years ago and did a bit of digging:
Amherst vs Dartmouth - College Search & Selection - College Confidential Forums
The OP in that thread had just turned 16 and was much further in the admissions process (she was already in the RD round with two acceptances.)
The age issue barely registered.