It's great that she's aiming to be a pilot. I've been in the industry 20 years and love my job. While there can be tough times along the way (low pay, long days in the beginning) there are some serious rewards (time off, money, ability to travel) for those who stick it out.
My opinion is that a college degree, while not required, will open up more opportunities than without one. I have friends without a college degree in aviation, and they have been limited to in career opportunities to companies with lower wages, worse working conditions and travel opportunities.
The point that bonanza made about not requiring an aviation degree is accurate. I have degree in aviation and I feel I understand what goes on behind the scenes better than those without one, but it's not required. A degree in business, finance, teaching, or whatever would provide a backup career if aviation doesn't suit her or she has a medical problem that precludes her from flying.
Most of all - she shouldn't give up! There are a lot of paths to a major airline, or whatever job she wants. I love going to work every time I go, and wouldn't trade the job for any other one.