Ultimately, there really isn't anything that can be done - you can't kick someone out because they look or smell a certain way if they're using a public utility the way it was meant to be used.
That "you smell" thing is basically code for "no homeless people." There is no objective smell-o-meter that indicates when someone is actually a threat to public welfare or something. And in settings where people did not know I was homeless, I did not see evidence that I actually smelled bad. They would ask me about my vacation plans while cutting my hair.
There's lots that can be done. How about more computers, for a start? If they're monopolizing 100 computers then how about 1000? Install public showers and laundry facilities, too. Add in a volunteer job training center. Run free programming classes and job interview tutorials. Resumé review classes would be great, too.
She isn't close to one. And I don't know of many libraries that are cool with you videoconferencing with instructors and pair programming 8 hrs/day.