If she rather enjoys the big buggers, there are some interesting options out there that she might want to consider.
Saddle fitter or master saddler, equine physioterrorist, sports massage therapist, farrier, nutritionist etc. You can be a sports coach too. Just like with human sports, more and more horsey people are recognising the importance of proper tack and treating muscles and other potential injuries-not just the obvious ones.
I've done an equine industry management degree. However, within the industry, more people are likely to be impressed by the proper BHS exams, or a proper Equine Science degree. Also, make sure you choose a decent college as mine was...errrr...not.
I have a friend who milks cows for a living-a herdsperson. She works bloody long hours, often gets crap living conditions, but actually quite a decent wage. Another friend works in equine insurance-an easier desk job, but with horsey people all around her.
If she's good at biology, there are biologists, conservationists, oceanographers...
No idea if that's of any help at all...really depends on what size hanimule she likes!