Let's be perfectly honest here: the hair on our body is there for a purpose - and it is up to the individual whether they wish to remove it or not - which we all accept.
She may not perspire as profusely as others, she may be meticulous in her personal hgyiene - the only thing 'wrong' as that some find it unsightly.
How many women who live in warm countries for example, shave the head on their hair? Very very few. Yet the scalp and back of neck have sweat glands, and long flowing locks on the head head don't tend to washed as often as the underarms.
The only thing 'wrong' with this -is that some people think it is aesthetically unpleasant. I find some people's facial looks aesthetically unpleasant but I wouldn't expect them to shave their head off to please me.
*yes... I am of course playing devils advocate -but all of the above is true*
Personally - I don't like the look - but unless she goes around sticking her oxters right into your face...... what's the problem.