Don't give her any money for now. Say no then monitor her behaviour. Does she get all stroppy with you or become aloof or will she respect your decision and carry on as normal?

If it's the former she's most likely looking for a sugar daddy so dump her. If not I'd contact the uni anyway like the others said and maybe come to an arrangement BUT first of all you need to suss her out with a firm no and see how she behaves towards you for a week or two.