If she's a couple of weeks from her period, the discharge is likely related to ovulation. Sorry to say, but the brownish color could be bromine. It seems to make its way into all our fluids. My husband had the surprise of his life when he coughed up brown phlegm.
Still, brownish staining could be related to her reproductive cycle. Google "brown stain ovulation" and there are many normal explanations for it. It may just have been chance that timed it shortly after starting magnascent.